According to a recent guest post on the Hitwise blog by Dustin Woodward, a Seattle-based SEO and web analytics specialist, the long tail of search might be even long than many of us assumed. Looking at Hitwise's data set of search terms used in the last three months, Woodard calculates that the top 1,000 search terms only account for about 10% of all search traffic. Woodard found about 14 million distinct search terms in Hitwise's data, with 'myspace' still being the most popular search query.

According to Woodard, the long tail of search is in fact far longer than most other reports have assumed. The top 100 search terms account for 5.7% of all search traffic and include keywords like 'myspace,' 'google,' 'bank of america,' and ' yahoo mail.' Those numbers are not unexpected. However, the top 1,000 search terms only account for 10.6% of all search traffic, and even the top 10,000 search terms only drive 18.5% of all search traffic.

Woodard also assumes that his data still underestimates the true size of the tail, as he deliberately filtered out all adult searches and only looked at data from the last three months. The fact that Hitwise relies on data from roughly 10 million U.S. users surely makes the data somewhat limited in its scope as well.

Also, looking at this data is yet another good reminder of the fact that search has replaced bookmarks and memorizing URLs for a lot of people. Most of the top search terms like 'google,' or 'usps,' are, after all, identical to their URLs.