2.3.1 Size of producer and consumer population

In most social media systems, producers and consumers are drawn from the same set of users. Users are producers one moment and consumers the next. However, differentiating between those who produce and consume content can be useful in comparing social media systems, even if the set of producers and consumers are not mutually exclusive.

Social media services vary in terms of their intended number of producers and consumers. An email is usually authored by just one person, whereas a wiki document is likely to be authored by several or even hundreds of people. An individually authored email might be sent to just one other person or be broadcasted to thousands. More generally, social media tools support different scales of production and consumption of digital objects. Table 2.1 provides some examples of social media systems, as well as some traditional media systems, and where various actions related to them fall within the producer and consumer size dimensions. You may notice that some systems show up in different places based on their usage scenario or the features that are being discussed.

Many social media tools help individuals or small groups interact. Text messaging, video chat, and personal or “direct” messaging within general-purpose social networking sites provide intimate communication channels comparable to phone calls and face-to-face office meetings. Social media can help individuals reach out to medium-sized groups of friends or acquaintances by broadcasting a personal message (e.g., a tweet sent to a user’s followers on Twitter; a post sent to a departmental email list; an instagram photo shared with family and friends) or allowing others to overhear a comment (like a post to someone’s Facebook feed). They can also allow individuals to potentially reach large groups through popular blog posts, podcasts, videos posted on sites like YouTube, or updates on Twitter by companies or celebrities with numerous followers.

Other social media tools help medium-sized groups reach out. Pages on social networking sites like Facebook and Twitter allow a group (i.e., your friends or those you follow) to create a personalized stream of information customized for you. Other tools like online surveys help aggregate information from many people for a small group of people or an individual analyzing the data. Group blogs or collections of related blogs about niche topics within the blogosphere allow a medium-sized number of bloggers and commenters to interact with one another. A number of different tools facilitate interaction between medium-sized groups whether they are part of a Facebook group, YouTube channel, Slack or Internet Relay Chat (IRC) room, or combinations of tools as in an enterprise social networking site. A department or workgroup wiki can allow members or co-workers to co- author materials that are of interest to their group.

Finally, some tools enable medium-sized producer groups to reach large consumer groups in a way similar to TV programs that take considerable effort to produce, but can reach large audiences. Some of these include online databases such as the Internet Movie Database (IMDB), where user-generated movie content is shared with the world; news sites like Reddit, where dozens to hundreds of people recommend a given news article that is consumed by much larger populations of read-only users; discussion forums, where posts by a few dozen active members may be seen by thousands of readers; and Wikipedia pages that are edited by dozens of people and read by thousands.

Some of the most interesting social media tools are those that help harness the power of the masses. For example, some recommender systems (e.g., Netflix, Spotify, Amazon, MovieLens) provide personalized suggestions of books, movies, or songs by comparing your ratings with ratings’ of other users. Other large groups help generate ideas that are used by medium-sized groups such as small businesses, corporate departments, or government agencies. For example, Kaggle is a website that allows anyone to start a sophisticated data analysis project with a reward so that many motivated data analysts can contribute ideas to solve their problems. NASA’s ClickWorkers help identify craters on Mars, Zooniverse contributors categorize the shapes of astronomical observations, and iNaturalist users report animal sightings.

Many of the most well-known social media sites allow large producer groups to interact with large consumer groups. Although there are many more Wikipedia readers than contributors, both groups are large. Online marketplaces like eBay allow the masses to sell and purchase goods. Meanwhile, social sharing sites like YouTube, Instagram and Flickr make it easy for large numbers of producers and even larger numbers of consumers to interact. While these sites often facilitate small group interaction, they also aggregate those interactions so that you can search and navigate through large corpora of user- generated content. Massively multiplayer games rely on having large numbers to produce content and social experiences that make use of the entertaining environment.

2.3.2 Pace of interaction

The pace at which interaction occurs is another important dimension along which researchers organize social media systems. Traditionally, researchers distinguished between asynchronous and synchronous communication. Asynchronous systems like email, discussion forums, and voicemail presume a staccato pattern of interaction spread out over hours or days or weeks. Though less immediate, these systems have the advantage of allowing you to schedule your participation without much coordination with other people who may be in a wide range of time zones. They also potentially encourage more careful contributions. In contrast, synchronous systems, like chat, instant messaging, videoconferencing, multiplayer games and graphical worlds, require that partners interact at the same time, as in face-to-face interactions and telephone calls. Although they require temporal coordination, they can create a richer environment for interaction as participants quickly react and adjust to one another’s signals in near real time. The pace of interaction has implications for the kinds of groups that form using each kind of tool. Global collaborations are often easier using asynchronous tools that don’t require people to change their sleeping habits. But some interactions need more rapid turn-taking to accomplish their goals.

More recently, the distinction has become increasingly blurred. For example, Twitter users often reply within minutes to another’s tweet, but it is completely acceptable to reply a day later as well. Replying to a Facebook post or status update on other social networking sites is similar in this regard. Tools like Google Hangouts are now integrated with the widely used Gmail web email system, again blurring the distinction between synchronous and asynchronous modes of communication by making it easy to move from one mode to the other. Apps like Marco Polo facilitate the sharing of video messages, which can also be viewed live. However, users’ varied expectations about the pace of interaction within these tools remains important for understanding social media environments.

2.3.3 Genre of basic elements

Digital objects, the basic elements of social media systems, vary in size and type. Twitter posts (i.e., tweets) are limited to 280 (initially 140) characters, whereas email messages are typically a few lines to a few paragraphs in length but can be even longer. This difference in size produces dramatically different patterns of interaction. Instant messaging design choices such as the size of the text box and messaging window promote brevity. Short messages are often directed to other people who are assumed to be busy and engaged in other activities. Meanwhile, MediaWiki (the wiki platform used by Wikipedia) supports six levels of headers and automatically generates a table of contents, making it relatively easy for you to create large pages to accommodate complex documents and concepts.

Using the digital objects supported by social media tools is another way for you to learn about the similarities and differences among them. Social media systems have often evolved around a distinct type of digital object: short posts or text messages from people and companies on Facebook and (even shorter) Twitter, videos at YouTube, photos at Instagram and Flickr, bookmarks (i.e., website URLs) at Pinterest, books at Amazon, music or podcasts at iTunes, TV shows at Hulu, messages in discussion forums or email lists, pages at Wikipedia, products at eBay, presentations at SlideShare, 3D objects in Second Life, and career professionals at LinkedIn. Over time, each has expanded into additional modes of interaction and types of digital objects. Instagram and flickr were once just for still images and both accept videos now. Business sites expand into lifestyle and leisure areas. Over time many functions have been rolled into the major platforms, marginalizing standalone platforms that specialize in just one mode of interaction or type of data. Each of these platforms provides you with different levels and mechanisms of engagement and interaction. For example, virtual worlds more closely model embodied physical interactions, where avatars can convey meaning through proximity and orientation [4]. They also introduce many of the burdens of face-to-face interaction, demanding attention to successfully puppet the avatar in interactions with other partners [5]. Although these differences may relate to the type of media (e.g., video, audio, text, 3D model), there are further distinctions within each type. Wikis support structured text elements like tables and bullets, whereas email typically does not. Some virtual worlds intended for children use cartoon characters, while multiplayer games with more mature users like World of Warcraft include realistic-looking creatures. Of course some social media systems like Facebook include many basic elements: profile pages, wall posts, personal messages, applications, instant messages, notes, groups, photos, tags, status updates, and so on. Wikipedia has user pages, talk pages, articles, edits, categories, and so forth. Even in these systems, identifying the basic elements of the system is important because they give you the building blocks for your interactions. They are also the building blocks of networks when they are connected together or exchanged, as you will learn throughout this book.

2.3.4 Control of basic elements

Social media systems provide different levels of control over their basic elements. They can restrict who can create, edit, read, invite, respond to, subscribe to, and share content of various types. Some systems differentiate between anonymous users, registered users, and those with special privileges such as administrators. For example, some discussion forums require that users log in before they post, but they allow anyone to read the messages created by the community. This helps reduce spam by creating a higher barrier to entry, while still allowing anyone access to the content. It also allows you to exclude participants you define as violating your social norms and expectations. In discussion communities that focus on sensitive topics (e.g., patient support groups), you can limit access to content until a person is registered, a process that may also require some type of approval process by current administrators. Other systems like eBay require users to provide validated credit card information before they can sell items. The more open a community, the more potential there is for deviant behavior as evidenced by the frequent spam sent to wikis, email lists and early forms of online discussion spaces like Usenet. However, closing a community off too much may reduce the number of contributors, whereas openness may attract high-quality contributions that combat the effects of spam and abuse. This happens in the many high-value pages in Wikipedia, where poor edits left by non-registered users are quickly reverted by other registered and non-registered users.

Choosing the right types of barriers to entry is an important part of online community building [6]. For example, in studying real-world communities, Ostrom [7] found that successful communities had clearly defined boundaries, largely to overcome problems associated with outsiders taking advantage of internally produced or maintained resources. Boundaries are also important in that they encourage frequent, ongoing interaction among group members. This is critical because repeated interaction is perhaps the single most important factor in encouraging cooperation [8]. If individuals are not likely to interact in the future, there is a huge temptation to behave selfishly and free ride. On the other hand, knowing that you will be interacting with others on a continual basis can lead you to create a reputation, which serves as a powerful deterrent to short-run, selfish behavior. Boundaries can have an impact on the kinds of interactions in which people are willing to engage because of the ways they shape the expected audience. Some media, like telephones and private postal mail, encourage the expectation that only a specific group of selected others will be the audience to your message. Other media, like tweets or Reddit posts, are likely to be seen by any number of unknown people. Further, some media prevent the identity of message creators to be known with certainty, if at all (e.g., pay phones or anonymous letters).

Control structures can heavily influence governance and the distributed or centralized nature of the environment. Although email lists, message boards, and Stack Overflow are all examples of asynchronous threaded conversation (see Section 2.4.1), their control structures are different. In centralized systems like email lists and many discussion forums, all communication flows through a single point, which is controllable by a single person (administrator) or small group who can wield dictatorial control over resources (messages) and access (who can subscribe). As a result, email list owners can remove people for inappropriate conduct or prevent spam or other inappropriate messages from being sent out or stored in the archive. They often serve as “benevolent dictators.” In contrast, distributed systems, like the Usenet network on the early text-only Internet, or the more current Blockchain platforms, are composed of hundreds of thousands of interlinked systems all interacting with a set of neighbors. Participants of sites like Stack Overflow use ratings to help identify high or low quality content. The lack of a central point of control makes it impossible or difficult for a member to exclude others or remove content.

The granularity of control is another important factor. Users of a wiki can edit individual characters of a shared document, whereas other systems limit users to authoring entire messages that cannot then be edited. Twitter users can follow another user and then receive all tweets from that user. In many systems, users can only edit their own content, whereas in other systems, such as wikis and Google Documents, users can edit others’ messages, documents, or objects. The level of granularity may differ for different user groups within the same system. For example, discussion boards on many websites create a preset number of containers (referred variously as “folders,” “topics,” “groups”) for interaction or leave control over the creation of new spaces in the hands of a small number of administrators. In contrast, email lists can be configured to allow anyone to start new threads simply by sending a new message that is not a reply to a previous message. Of course, systems in which users can create spaces with little restraint often contain many more of such spaces. The pace of interaction can be crossed with the granularity of user control to characterize systems (see Table 2.2).

2.3.5 Types of connections

There are many ways that the basic elements of social media systems can be connected. It is important to understand these connections or “ties” in order to construct and understand networks from each kind of social media system. The next chapter goes deep into the theory and language of networks. This section describes the many types of connections that exist in social media systems and explores the ways collections of these connections create larger social systems that you can analyze with the math, tools, and insights of social network analysis.

The basic elements of many social media systems can be connected to one another explicitly or implicitly. Users intentionally and knowingly create explicit connections, whereas implicit connections are inferred from the details of many digital traces. Perhaps the most common type of explicit social media connection is friending on social networking sites, where both people must approve the connection before it is realized. Other examples of explicit connections are following another user on Twitter, hyperlinking a wiki page to another page, tagging two photos or videos with the same tag, and adding someone to a text chat group.

Implicit connections can be inferred when a user sends another user an email message, “favorites” content (and by extension its author), replies to a discussion post, or “Likes,” “Loves,” or “Upvotes” another user or their content as some sites allow. Although these actions are intentional, they are not performed with the explicit intention of creating a connection with the person. Other more subtle implicit connections can be identified, such as connecting people who “hang out” in the same discussion forums or Facebook groups, or who edit the same wiki pages, or people can be connected by the books they both purchased from an online bookstore. These individuals may not know one another, but they are connected by their shared interests, locations and activities. Other connections can be inferred from data that are often not public but are available to the hosts or owners of social media systems such as reading patterns of discussion forums, music downloads, patterns of telephone calls, and location information. Smartphones with location sensors allow platforms to create implicit links between people who go to similar types of places, even if they do not go there at the same time. In innumerable ways, users now leave behind traces that form an intricate web connecting every person with the other people, locations, and digital objects around them.

An important distinction among the types of connections people can create using social media platforms is between directed and undirected links. If you and another person become friends on Facebook, the connection is a mutual one. In other words, it is undirected. Likewise, if you both are tagged as an “expert,” then you are connected by an association that is mutual and thus undirected. In contrast, some systems like Twitter allow people to follow other users without first gaining those users’ approval. This creates a different type of tie, where the directionality of the tie is important (i.e., who is following whom). Directed ties are also created when a person invites another person, favorites content, and creates a hyperlink from one page pointing to another page. In all of these cases, connections flow from one person or object to another and may not necessarily be reciprocated.

Finally, connections mean different things and can have different weights and values. For example, two people on Facebook can either be friends or not be friends; it is a binary connection that is either on or off. In contrast, two Facebook friends may send each other personal messages. The strength of their messaging connection could be measured based on the number of messages or the number of different days they each sent one another messages. These are examples of weighted connections that vary in intensity. These weights often contain important information about the strength of a tie. For example, if Marc sent 10 messages to Ben last week and only 1 to Derek and 3 to Itai, it is probably safe to say that last week Marc was more strongly connected to Ben than to Derek and Itai (at least via that messaging medium).

The examples shared so far primarily connect people to each other, objects to each other, or people to objects. Recently, location has become an expanding part of social media services, allowing connections to be created between people, objects, and places. Smartphones are opening a new era of social media that integrates information about location and activity in novel and powerful ways. New kinds of ties are being formed by just being in the same place as someone else, even at different times. Just having a phone or a laptop nearby someone else’s can create implicit connections.

2.3.6 Retention of content

Social media systems also vary in how long content is retained. On one end of the spectrum are systems like wikis that typically create a permanent history of all actions that occurred in the system. Not only is each action recorded and stored, it is made available on article history pages and user contribution pages. At the other end of the spectrum, some instant messaging or voice-over Internet Protocol (IP) systems do not centrally record the interactions at all, allowing for fleeting exchanges more reminiscent of most face-to-face conversations. Users at the end points to these conversations can, of course, record them but extra effort must be taken. Many social media systems fall somewhere in the middle. For example, as of this writing, searches of the Twitter network via the public free API used by many software analysis tools can only receive from the most recent 8 or 9 days. The horizon of the past in these systems is in flux as data volumes grow along with information processing capacity and commercial requirements. The desire to add social media data to our long-term cultural memory has prompted interesting partnerships, as evidenced by the agreement between Twitter and the Library of Congress. However, these arrangements have not made widespread long-term historical social media data accessible, and the original plan of storing every tweet was rescinded so that only selected tweets are now stored. Critics warn that decades of social history are less accessible in the digital age than prior eras with more durable archival copies of physical books, movies, newspapers and audio recordings. Ironically, digital culture may have less durability than pre-digital culture, making the work of future historians a difficult one.

Some types of social media systems vary in their retention policies depending on specific product or user settings. For example, some instant messaging clients do not archive conversations, whereas other clients retain them by default. SnapChat promised users that their video messages will be seen only once (or twice) and will be deleted shortly thereafter. In contrast, some email lists create a searchable archive of prior messages sent to the list (while some others do not by choice). However, it is important to realize that even if there is no centralized archive, individuals at the end points of these services may archive content and make it public at a later date. Such was the case when Usenet content was made easily searchable by Google, upsetting some contributors who never imagined their posts would become easily searchable and available to the masses. People can collect email messages, record Skype calls, log chat sessions, capture screenshots, and collect most digital content fairly easily. We are now living in a world of easy data collection, retention, analysis, and publication suggesting prudence in using social media systems. Choose your words carefully; they may outlive you.

2.4.1 Asynchronous threaded conversation

Asynchronous threaded conversations take on many forms such as email, email lists, Usenet newsgroups, discussion forums, and web boards. This form of social media has been the backbone of online communities since before the Internet and it continues to play an essential role in a variety of settings both within organizations and on the public web. Even newer forms of social media such as social networking sites, social sharing sites, and virtual worlds often have asynchronous threaded conversations embedded within them to facilitate discussions (e.g., Facebook groups). Although there are several flavors of threaded conversation, they share some key properties in that they are asynchronous, messages are labeled with an associated address or username, typically, with a single author, and other authors can reply to these messages and reply to others’ replies creating conversation “threads.” Authors do not typically edit one another’s messages or even their own messages after (and some say before) it has been initially contributed. This basic structure has proven to be extremely versatile, supporting a wide range of individual, organizational, and community needs.

Threaded conversations, in all their forms, create implicit ties that connect senders and receivers of content in what is often called a “reply network” or “reply graph.” These reply networks can be analyzed to identify important relationships, distinctive patterns of connections that reflect social roles, subgroups or clusters of people, interdepartmental connections, and many other important relationships. Next are brief descriptions of some of the most important asynchronous threaded conversation systems. See Chapters 9 and 10 for a more complete history and description.

2.4.2 Synchronous conversation

Synchronous conversations such as text messaging, chat, instant messaging, and audio and video conferencing differ from asynchronous conversations in that they occur in real time. Precursors to these Internet-based conversations occurred via telegraph, phone, two-way radios, and similar technologies. UNIX talk messaging, first used in the early 1970s, was among the first instantiations of text-based synchronous conversations based on computer networks. This simple system is the early precursor to chat and instant messaging, initially allowing two people to share a text stream, both users typing characters that would appear intermingled in the same space. Later innovations and refinements separated the text streams and evolved into the many forms of short messaging and texting services available today. Facebook Messenger, Zoom, Apple Facetime, Skype, WeChat, WhatsApp, and other synchronous conversation tools today have added support for small group conversations, whereas others such as Internet Relay Chat enable large scale conversations where anyone who “tunes” to a specific “channel” is able to join.

2.4.3 The World Wide Web

The largest public, machine-readable network is the World Wide Web where web content, such as web pages, and documents, such as images (identified by their Uniform Resource Locator or URL), are connected together by hyperlinks. The World Wide Web, WWW, or just “the web,” was initially conceived by Tim Berners-Lee in the 1980s, but it was not realized until the 1990s. The WWW was the first platform to integrate the concepts of hypertext, developed in the 1960s by Ted Nelson (Xanadu) and Douglas Engelbart (oN-Line System [NLS]), with the Internet [11]. The result was a highly flexible platform that allowed people to view web content hosted on servers throughout the world with the use of a web browser. Today the web is the primary platform upon which most of the social media tools are built. In this section we focus primarily on traditional websites such as corporate, organizational, and government websites, homepages, and documents (e.g., images and pdf files).

Although you may not realize it, network analysis already plays a role in billions of people’s everyday lives when they search the web via Google. As the amount of content on the web increased, search engines became essential for making content on the web discoverable. Early search engines looked only within the text of each web page (and its associated metadata fields) to determine its relevance. The first generation of search engines, like Alta Vista, built an index of all the words on millions of webpages and matched them to search queries. Google made a breakthrough in the quality of its results by developing its PageRank algorithm, which determines how important a page on the web is based on its position in the web’s wider network of connected pages. At its core, the PageRank algorithm views a link to a page as a “vote” for that page’s importance, so that pages with many incoming links score well. In addition, it considers the importance of each of the incoming links: receiving a link from a highly linked-to site counts more than receiving a link from an unknown site. This and related concepts are captured in various measures of the “centrality” of a vertex within a network as discussed in Chapter 6.

2.4.4 Collaborative authoring

Several social media tools facilitate the collaborative authoring of documents and repositories, enabling small groups and even communities of thousands to effectively create, maintain, and organize documents and document repositories.

2.4.5 Blogs and podcasts

Blogging is a special form of web page publication. Deceptively simple, a blog is essentially a low-cost mechanism for publication of rich digital content. Early blogs presented a series of text messages or “posts” in reverse chronological order so the most recent post was always at the top of the page. Today, a blog is a rich platform for content presentation and commentary. Blogs may contain textual content that are now complemented with pictures, video, and audio. Blogs present this content along with search, functionality for readers to comment on each blog post, tags to categorize posts, pointers to related blogs (i.e., blogrolls), and a range of applications and widgets. Popular tools like WordPress, Drupal, and Blogger make blogging essentially free and widely available. They are also commonly embedded within larger sites.

Blogs and by extension bloggers are now often able to build audiences that rival pre-digital media and challenge more established information providers, particularly in the news arena where current information is paramount. Blogs and bloggers are seen as potentially powerful makers and breakers of brands, political candidates, and news stories. They also serve as micropublishing platforms for families sharing stories and photos of their children and niche interest groups exploring an obscure topic. A single blog may be authored by an individual or a handpicked set of authors. Others participate via comments or by linking their own blog to other blogs, creating aggregated collection of interconnected blogs often referred to as the blogosphere. Specialized search engines collect the messages from much of the blogosphere, using the unique properties of blog links (called trackbacks) and number of comments to assign credibility scores to blogs. Because the connections can be automatically captured using web crawlers, researchers have analyzed the blogosphere to better understand issues like the nature of political discourse in the highly divisive politics of the United States [12], as well as other areas such as Iran [13].

2.4.6 Social sharing

Social sharing sites are designed to allow individuals to share content, typically of a certain type (e.g., videos, photos, websites). They provide an alternative to purposeful searching for content on search engines by allowing a community of peers to collaboratively identify and share interesting content. They are a modern incarnation of browsing, where the masses decide what is on the shelf. While some services are focused almost solely on social sharing (e.g., Mix, Goodreads), social sharing features often show up as a feature on other social media platforms (e.g., photo sharing on Facebook). Social sharing sites may or may not allow users to create content. For example, YouTube allows anyone to upload videos, while Hulu users can only share what they’ve been watching.

2.4.7 Social networking services

In 1971, Les Earnest wrote the “finger” program that allowed users of a system to check on another user’s status. When a user requested it through the finger program, a file named “.plan” would be displayed to other users. This file soon became the business card and office door for many early users of the Internet and the networks that preceded it. Some users even updated the file regularly to note their current location, activity, and state of mind. This simple status and profile system evolved over time and inspired the creation of systems that allow people to present themselves to others. Modern incarnations, called social networking services, allow people to share contact information, text, images, and videos about themselves with their self-identified friends or followers. Early popular examples like Friendster and MySpace established the basic outlines of the social network feature set in which users “friend” other users, enabling them to share content and receive updates about each others’ activity.

2.4.8 Online markets and production

Many social media sites facilitate the creation, evaluation, funding, and exchange of goods and services.

2.4.9 Idea generation

Organizations are increasingly looking for ways to benefit from the collective intelligence of the masses. Several social media sites use “idea generation” tools to help solicit and evaluate new ideas. Companies like IdeaConnection allow organizations to post proprietary challenges to a community of problem solvers. If someone solves the problem, that person is awarded a specified dollar amount. More domain-specific examples include Kaggle and TopCoder where users compete against each other for prizes in data analysis tasks or coding tasks. These sites create networks that connect people based on shared projects and challenges. If nobody solves the problem, no money is exchanged. Other tools by companies like Chaordix and IdeaScale allow users to post ideas and vote on others’ ideas, helping the best ones bubble to the top. These services create networks that connect people based on who voted on whose ideas. They also create networks that connect ideas to other ideas based on the number of people who liked both ideas.

2.4.10 Games and virtual worlds

Virtual worlds, graphical worlds, and massively multiplayer games attempt to model physical places as well as face-to-face interaction. Modern virtual worlds allow users to build new spaces, create objects, and use powerful programming languages to automate their behavior. These sophisticated forms of social media create remarkably rich collections of networks. Even services offering relatively simple game experiences like card games and backgammon offer sophisticated ways of creating friend networks, teams, and rankings. Game systems commonly allow users to create affiliation networks when players join clubs, guilds, tribes, or teams. Within the game play are other processes that create networks as records are created when users shoot or kill one another or trade less lethal materials.

2.4.11 Mobile services

The next step from virtual reality is into physical reality. Recent waves of social media tools integrate hardware and software tools to enable users to annotate physical locations. Smartphones track their location via Global Positioning System (GPS), cell tower location services, wireless networks, and beacons, supporting experiences tied to users’ location in space. Once the device has an accurate sense of its location, that information can be associated with all the digital objects created with the device. Photos can be easily linked to the place on earth where they were taken. Restaurant reviews can be associated with a map of the location of the restaurant. A comment can be linked to where it was made. In addition, mobile devices lead to the creation of more social media content because it can be created and captured in spare moments and when notable events unfold.

Location is key to social media services that want to provide contextual information about the world immediately around users. Increasingly, this is done via Augmented Reality (AR) features that map virtual objects (e.g., images) and information onto real-world objects and scenes. Pointing a camera at an object can now reveal relevant information. Furthermore, a host of additional sensors provide functionality that can be called upon by new social media services. These include still and video cameras, audio and motion sensors, accelerometers that detect motion, and tools that enable device-to-device connections. This combined functionality and the proliferation of smart devices promises a bright future for mobile social media tools.