As we have discussed throughout the book, the long tail is an important part of SEO. Metrics are available for diagnosing the health of your long tail search traffic. Here are some that were developed by Brian Klais of Netconcepts.
This is the percentage of your natural search traffic that comes from brand keywords versus non-brand keywords.
If the ratio is high and most of your traffic is coming from searches for your brand, this signals that your SEO is fundamentally broken. The lower the ratio, the more of the long tail of natural search you likely are capturing. This metric is an excellent gauge of the success of your optimization initiatives.
This is the number of unique (nonduplicate) web pages crawled by search engine spiders such as Googlebot. Your website is like your virtual sales force, bringing in prospects from the search engines. Think of each unique page as one of your virtual salespeople. The more unique pages you have, the more opportunities you have to sell through the search engines.
This is the percentage of unique pages that yield search-delivered traffic in a given month.
This ratio essentially is a key driver of the length of your long tail of natural search. The more pages yielding traffic from search engines, the healthier your SEO program is. If only a small portion of your website is delivering searchers to your door, most of your pages—your virtual salespeople—are warming the bench instead of working hard for you. You can think of these non-performing pages as “freeloaders.”
This is the average number of keywords each page (minus the freeloaders) yields in a given month. Put another way, it is the ratio of keywords to pages yielding search traffic.
The higher your keyword yield, the more of the long tail of natural search your site will capture. In other words, the more keywords each yielding page attracts or targets, the longer your tail. So, an average of eight search terms per page indicates pages with much broader appeal to the engines than, say, three search terms per page. The average online retailer in a Netconcepts study on the long tail of natural search (http://www.netconcepts.com/learn/ChasingTheLongTail.pdf) had 2.4 keywords per page.
This is the ratio of search-engine-delivered visitors to search terms. This metric indicates how much traffic each keyword drives and is a function of your rankings in the SERPs. Put another way, this metric determines the height or thickness of your long tail.
The average merchant in the aforementioned Netconcepts study obtained 1.9 visitors per keyword.
This is the ratio of pages indexed to unique crawled pages. If a page gets crawled by Googlebot, that doesn’t guarantee it will show up in Google’s index. A low ratio can mean your site doesn’t carry much weight in Google’s eyes.
Calculated for each search engine separately, this is how much traffic the engine delivers for every page it crawls.
Each search engine has a different audience size. This metric helps you fairly compare the referral traffic you get from each. The Netconcepts study found that Bing and Yahoo! tended to crawl significantly more pages, but the yield per crawled page from Google was typically significantly higher.
As you optimize your site through multiple iterations, watch the aforementioned KPIs to ensure that you’re heading in the right direction. Those who are not privy to these metrics will have a much harder time capturing the long tail of SEO.