For most companies, the initial steps in setting an SEO strategy focus on defining the product priorities and the target markets. As those issues are typically driven by the particular concerns of specific businesses, we're going to focus this discussion on the next step in the strategy process, that is, determining which keywords and phrases are most likely to deliver the type of traffic the site needs.

Start the keyword selection process by thinking big — don't restrict yourself by trying to formulate the most exact and narrow keyphrases; rather, come up with a large set of potentially relevant words and phrases that we can then whittle down to the optimal set. Look at the product or service; consider the language variants, the terms of art, and the related concepts. Make a list and add to it over time; this is one of those exercises that tends to benefit from having a bit of time to think about things and then process them. It's also a good idea to get other people involved to avoid subjective bias.

After you've assembled your preliminary list, it's best to take some time and do some research to make sure you haven't missed any candidate words or phrases. To accomplish this we'll use several techniques. One of the easiest ways to search for keyphrase ideas is to look at what is being done by your competitors. To do this, simply identify a set of competing sites, visit their sites, and then view the source code to see what, if anything, is in their metadata.

A useful tool for assisting with keyword selection is the Google AdWords Keyword Tool. It's free of charge and, despite the name, it's useful for a lot more than AdWords. Here's how to use it:

The tool will then present you with a (potentially) long list of words and phrases that are related to your ideas, along with data about how frequently they were used by people searching on the Google search engine.

As an alternative to entering words or phrases as your starting point for keyword ideas, you can also point the tool to a particular web address. To use the website discovery tool, follow these steps:

Again, the tool presents you with a list of potential words and phrases, this time based on the content of a specific web page — a useful way to cross check your keyword ideas and discover new potential sources of traffic.

In addition to the list of words and phrases, the AdWords Keyword Tool also provides other useful information. The next screenshot shows a sample result set. The six words at the top, located under the heading Search terms, are the six words I entered into the Word or phrase field. The 800 words and phrases under the heading Keyword ideas, are those suggested by Google.

The two columns to the right-hand side of the keywords are important. The first, Local Monthly Searches, displays the number of times this keyword or phrase was entered into the Google search engine by a visitor; the number is a monthly average over the last 12 months. Click the combo box labeled Sorted by Relevance to change the sort criteria for the list of keywords, allowing you to easily spot the most popular keywords. You can now identify with confidence the keywords that are associated with the most traffic.

The final column, Local Search Trends, contains 12 bars that display the relative search volume for the keyword in each of the last 12 months — a useful way of identifying trending terms.

Now that you have a set of key words that have a known ability to deliver traffic, you need to select which ones to target for your efforts. You're not going to be able to target all the relevant, or even necessarily the most desirable, keyphrases. For most people, this comes down to a cost/benefit analysis. Be selective and pick a limited set that represents the best choices for your site.

If you are like most people, at this point you will want to get your keywords data out of the Google Keyword Tool and into a tool that allows you to manipulate the data more easily. Google makes this easy to do; simply click the checkbox next to the words you want to keep then click the Download button and select the format for the file. You will then be able to open the keyword list and manipulate it in Excel, or your preferred spreadsheet program. If you don't see the Download option, log in to Google.

The decision of which keyphrases are the best choice for any particular site is a subjective one. If you are concerned about fast results or responding to seasonal demand patterns, you will be looking at trending keyphrases and those with high volume. If you are looking at long term brand building or product awareness, you may be selecting words that most accurately describe your products or services, regardless of whether those terms generate less traffic than other less specific keywords.

You can be certain that you are not the only person who has determined that a particular keyphrase is valuable. There will always be competition. While you can blindly pursue the highest volume keyphrases without consideration of the competition for those phrases, we cannot recommend that approach; it is a recipe for slow, or no, results. If you wish to target high traffic and high competition keywords, be prepared for a long fight for ranking (and thereafter an on-going struggle to maintain those rankings). The low-hanging fruit is in the long tail, that is, the keyphrases found near the narrow end of the search query frequency or competition distribution.

Chasing the long tail has several advantages:

Reaping the rewards of a long tail is much easier than competing against large numbers of sites for broad key words. While there are literally millions of sites competing for the phrase "caribbean villa", there are significantly fewer chasing the phrase "2 bedroom villa rental in Curacao". Moreover, if someone is looking specifically to rent a "2 bedroom villa in Curacao", and you have one available on your site, then this is just the sort of visitor you want. In contrast, if someone is simply searching for "caribbean villa", you have no idea what island is of interest, or even whether they want to rent or buy — in other words, they may not be the customers you are looking for.

While keyphrase selection is more an art than a science, there are metrics you can apply to the process. One of the most useful is known as the Keyword Effectiveness Index, or KEI.

KEI, in its simplest form, is a comparison of the potential search volume for a term relative to the number of pages competing for that term. There are multiple methodologies for arriving at KEI; which approach you prefer will typically depend on your personal SEO strategy. The most direct KEI formula looks as follows:

KEI = V²/C

Where:

In other words, KEI is the square of the search query volume divided by the number of competing pages.

Let's put the formula into practice: If you look at the Google Keyword Tool screenshot earlier in this chapter, you can see that the search term last minute travel generated an average of 201,000 queries per month over the last year; that's the first piece of data we need. Now, we need to find the number of pages competing. To do that, simply go to Google and run a search for last minute travel. At the top of the search results, Google tells you how many results were found, as seen in the following screenshot:

Now we have both of the numbers we need:

201,000²/26,100,000 = 1547.9

Accordingly, using this measure of keyword effectiveness, we can say that the phrase last minute travel has a KEI of 1547.9. We could then run the rest of our candidate keyphrases through the same exercise and create an objective benchmark that could be used to compare the relative attractiveness of each of the various words and phrases.

In the example given, we looked to Google.com for data. Depending on your target markets, you may well want to check instead the country-specific versions of Google. Note that your choice of geographic filters in the Google Keyword Tool should be consistent with your selection of the appropriate Google search engine. In the example given, the Keyword Tool was set to produce results relevant to the United States, and the competition data was then taken from Google.com, as it is by far the most popular choice for web searches in the U.S.; you should apply a similar logic if you are targeting non-U.S., or non-English-speaking markets.

As noted previously, there are multiple approaches to calculating KEI. One alternative addresses (at least in part) the most common criticism of KEI, that is, that KEI does not take into account the quality of the competition. Use this variation on the KEI formula to restrict your competition analysis to only the more aggressive competitors. To narrow the analysis to a more accurate list of serious competitors, search only for those pages that use the keyphrase in the page titles, rather than using the gross search results figure from Google. To do this, we modify our search query for competing pages. Instead of searching for all mentions of the phrase, we can use the Google search operator allintitle. Your modified search query to Google will look like this: allintitle: last minute travel. With this operator in the query, you will get a count of only those pages where the term last minute travel is included in the page title — a reasonably effective way of narrowing things down to the number of sites that are making a serious effort to compete for traffic from the keyphrase. In the example used here, the competition number drops from over 26 million to 767,000.

Another useful variation on the KEI formula is to factor in a relevance rating for each keyphrase. To do this, you must first rate all the prospective keyphrases for relevance. This is a subjective exercise, so any criteria you use is fine, as long as it is logically consistent. The easiest solution is to simply rate each keyword on a scale of 1 to 3, where 1 is the least relevant, and 3 is the most relevant. To apply, modify the formula as follows:

KEI = (V²/C)R

Where:

In other words, take the square of the search query volume, divide it by the number of competing pages, and then finally multiple the result by the relevance ranking.

Of course, you can always combine both of these variations, or you can create your own version of this popular formula. Regardless of which path you choose, using an objective metric to assess the possible keyphrases is a useful exercise. Not only does it allow you to impose a transparent methodology to assessing keywords, but also helps decision makers formulate an appropriate cost/benefit analysis for chasing particular keyphrases.

The major search engines are, to varying degrees, capable of identifying similar and related words. If you are aware of this, you can use it to your advantage in both your keyphrase selection strategy and in your content creation. Two techniques are of primary use here: stemming and word variants.

Stemming is simply reducing a word to its root form. To take a simple example, the word "take" has multiple acceptable forms: take, taken, taking, took. Other words have irregular plural forms, for example, "child" and "children." Most search engines will recognize the various grammatical forms and derivations and return them when a user searches for the root word, though they will not be given the same relevance as the root.

In terms of keyword strategy, this presents an opportunity. Your search for the optimal keywords should also look at the word roots that are relevant to your site and compare the traffic for the roots and the other forms. Based on the results, you can then decide whether to target the root, or a specific derivation. Stemming also gives webmasters more latitude when writing content, empowering the use of alternative forms that are closely related. By varying your word choice in your content, you can avoid boring repetitions that alienate readers and keyword stuffing that alienates search engines.

Variants, in this context, refers to the use of synonyms, alternative spellings, and common misspellings. As with stemming, you should always investigate the options presented by variants in your assessment of the optimal keyphrases. Synonym usage, in particular, can often provide very fertile ground. Differences in British and American English is also an area that should be investigated, particularly where your target markets use mixed (some spell it one way, others another) spellings. Misspellings can also provide some pleasant surprises, opening up low competition avenues to search engine traffic.