Google's search share dropped a full percentage point in July to 43.7% from 44.7%, according to comScore. This drop marks the first time in a full calendar year that Google's share of all search engine queries has fallen.
According to comScore, Google's competitors picked up the slack, splitting the percentage point evenly. Yahoo's share was 28.8%, up from 28.5% in June '06, and AOL's share was 5.9%, up from 5.6% in June '06. Ask Network's share increased to 5.4%, up from 5.1% in June '06.
Bear Sterns analyst Robert Peck warned investors last week that "a full percentage loss in domestic market could signal a topping point as we do not expect Google's aggressive market share gains to continue in perpetuity."
However, he also noted that Google grew searches by 55.7% year-over-year, compared to an overall industry growth rate of 30%.
It's also important to note that comScore's ranking methodology includes all searches across a company's properties. So, for example, comScore counts not just Google search but also Google image search, not just AOL.com but also all Time Warner properties, like Netscape.com.
Update: Nielsen//NetRatings released their metrics today, and they've got Google controlling 49.2% of all US searches. Yahoo has 23.8%, MSN 9.6%, AOL 6.3% and Ask 2.6%.