Google is the second most popular site with 494 million unique visitors and Yahoo ranks third with 477 million visitors.
Microsoft also led in March 2006, and its lead over Google was bigger. Microsoft had almost 539 million unique visitors compared with almost 496 million for Google. Third place went to Yahoo with a little more than 480 million.
However, the difference in online ad revenue between Microsoft and its two rivals is massive, a sign that, despite heavy investments in the past three years, Microsoft isn't close to matching their ability to monetize Web site traffic, especially Google's torrid growth in the search engine space.
In the quarter ended Sept. 30, 2006, Google's revenue, which comes mostly from search engine ads, grew 70% to $2.69 billion, while Yahoo's revenue, mostly derived from various forms of online ads, came in at $1.58 billion, up 19%. By comparison, in that same quarter, Microsoft's Online Services Business, which includes online ad and Internet access sales, generated $539 million in revenue, down from $564 million in the same quarter the previous year.