Google continues to lead search in the U.S.

comScore, Inc. has released its monthly comScore qSearch analysis of the U.S. search marketplace. The April 2011 qSearch data reflect the impact of Yahoo! Search Direct, Yahoo!’s new feature that delivers search results in real-time while users type their query. Yahoo! Search Direct was available only on Yahoo! U.S. Web Search for the month of April.

Google Sites led the U.S. explicit core search market in April with 65.4 percent market share, followed by Yahoo! Sites with 15.9 percent (up 0.2 percentage points) and Microsoft Sites with 14.1 percent (up 0.2 percentage points). Ask Network accounted for 3.0 percent of explicit core searches, followed by AOL, Inc. with 1.5 percent. These numbers exclude contextually driven searches that do not reflect specific user intent to interact with the search results.

The study says that more than 16.2 billion explicit core searches were conducted in April. Google Sites ranked first with 10.7 billion searches, followed by Yahoo! Sites with 2.6 billion, Microsoft Sites with 2.3 billion, Ask Network with 491 million and AOL, Inc. with 248 million.

In the total core search front Google Sites accounted for 64.2 percent of total queries conducted (up 0.1 percentage points), followed by Yahoo! Sites with 17.9 percent and Microsoft Sites with 13.8 percent (up 0.2 percentage points). Ask Network comprised 2.7 percent of total search queries, followed by AOL, Inc. with 1.4 percent.

“Total Core Search” is based on the five major search engines, including partner searches, cross-channel searches and contextual searches. Searches for mapping, local directory, and user-generated video sites that are not on the core domain of the five search engines are not included in these numbers.

Americans conducted more than 18.0 billion total core search queries in April. Google Sites ranked first with 11.6 billion searches, followed by Yahoo! Sites with 3.2 billion and Microsoft Sites with 2.5 billion.