Google has surpassed Yahoo to become the most popular website in the U.S., according to Internet tracking firm ComScore Inc.'s rankings by the number of unique monthly visitors.
Google Inc. has long been the Internet's leader in search, but its audience has trailed Yahoo Inc.'s when counting other services such as e-mail and photo sharing.
April's numbers, which ComScore plans to formally release today, show Google on top for the first time.
The lead is tiny -- 466,000 visitors out of about 141 million apiece. And while such measures are good as a gauge, they aren't known for precision.
Still, ComScore's finding is one more hint of Mountain View, Calif.-based Google's dominance over Sunnyvale, Calif.-based Yahoo.
Google now has the Picasa online photo-sharing service competing with Flickr from Yahoo. Google also has launched a site on finance, and its Gmail e-mail service keeps growing -- and competing with Yahoo.
Google's $1.76-billion purchase of YouTube in November 2006 gave it the leading video-sharing website.
According to ComScore, Google's unique U.S. audience in April was 141.1 million, an 18% increase from the same month in 2007. Yahoo's audience grew 7%, to 140.6 million. Microsoft Corp. was third at about 121 million.
Even so, Yahoo still leads in page views, meaning visitors spend more time there or return more often. Many Google users make a simple search request and quickly go elsewhere based on the results. Yahoo had 33.6 billion page views to Google's 28.7 billion.