ComScore Inc., seeking to give its customers more detailed information on the habits of Web users, changed its method of measuring Internet searches to include queries sent to search engines by other websites.
Under the new system, Google Inc.'s share of queries rose to 55.2% from 46.2% a year earlier. Yahoo Inc.'s share fell to 23.5% from 29.8% a year ago, the biggest decline among the top five search engines, Reston, Va.-based ComScore said Monday.
Internet search engines make money by displaying ads that are related to the user's query, with companies paying a fee when users click on the links. ComScore also said it would start measuring search queries at sites owned by companies such as Amazon.com Inc. and EBay Inc. and would track the Web-search market in as many as 15 countries by the end of the year.
"The global market is growing much more quickly," said James Lamberti, senior vice president of search solutions at ComScore. "You're seeing a major amount of activity outside the U.S."
ComScore will also tally queries for images, maps and local directory listings, giving more detailed information on what people are looking for. The company, whose data are used by advertisers and financial analysts, competes with NetRatings, owned by Dutch media company Nielsen Co. In July, NetRatings started publishing data on the time users spend on websites.
Yahoo's share of searches declined from 23.8% in June, while Mountain View, Calif.-based Google had 54.9% that month, ComScore said.
Microsoft Corp., which runs the MSN website, had 12.3% of queries in July, compared with 12.4% a year ago and 12.2% in June, ComScore said.
Yahoo, owner of the most-visited U.S. website, blamed its loss of share on the change in ComScore's methods. Project Panama, an advertising program introduced by the Sunnyvale, Calif.-based company in February, may spur growth, spokeswoman Kathryn Kelly said. The program is designed to make advertisers' links more relevant and more likely to be clicked.
"Our affiliate search hasn't been as strong as Google's in the past," Kelly said. "We'll have to wait and watch."
Nielsen/NetRatings also said that Yahoo's share of the search market fell, to 20.1% in July from 23.8% a year ago. Google kept its top ranking with a 53.3% share, up from 49.2% a year earlier.
Nielsen's figures don't include searches from other sites.
Yahoo shares fell 20 cents to $23.34, Google declined $2.12 to $497.92, and Microsoft rose 1 cent to $28.26.
IAC/InteractiveCorp.'s Ask.com had 4.7% of the market in July, compared with 5% a year ago and 4.6% in June. Time Warner Inc.'s sites had 4.4% of queries, down from 6.6% a year earlier and 4.5% in June, ComScore said.
ComScore's new method is a better representation of the market, said Brad Goldberg, a general manager for Microsoft's Live Search. It "more accurately measures search traffic sources."
To measure market share, ComScore uses a group of 2 million Internet users who have agreed to have their activity on the Web monitored by the company. ComScore uses this sample to produce estimates for all Internet users.