MediaPost: WebSideStory Search Report Crowns Google, Leaving Yahoo! In The Lurch

When comparing stats, it's important to recognize the differences in source methodologies. The latest data from WebSideStory's StatMarket, giving Google a 41 percent share of inbound search referrals is very different than the Nielsen//NetRatings reach numbers, or the percentage of search numbers used by comScore.

Nielson looks at usage over a month, so their reach percentages exceed 100 (due to people using more than one engine). ComScore uses a panel and looks at searcher totals.

WebSideStory looks at a large number of web sites to count inbound clicks. So, for example, if a searcher uses Google once, comScore counts that once, just as it would for MSN or Yahoo. However if Google searchers click on links more often within the search results, Google will skew higher when we look at server logs.