Every month about this time comScore releases the search engine rankings data, and I report it here. These are not the actual search engine rankings that you see when you search at a search engine, which are constantly changing.

comScore, Inc. (NASDAQ: SCOR) , a leader in measuring the digital world, releases its comScore qSearch analysis of the U.S. search marketplace. In February 2010, Americans conducted 14.5 billion core searches, with Google Sites accounting for 65.5 percent search market share.

Websites owned by Google continues to lead the search market in the United States. In February 2010, Google had 65.5 percent of the searches conducted online, followed by websites owned by Yahoo! (16.8 percent), and websites owned by Microsoft (11.5 percent). The Ask Network captured 3.7 percent of the search market, followed by AOL LLC with 2.5 percent.

  comScore Core Search Report*
  February 2010 vs. January 2010
  Total U.S. - Home/Work/University Locations
  Source: comScore qSearch
  ------------------------
                                 Share of Searches (%)
                                 ---------------------
                                                      Point Change
                                                       Feb-10 vs.
  Core Search Entity          Jan-10       Feb-10        Jan-10
  ------------------          ------       ------      -----------
  Total Core Search           100.0%        100.0%         N/A
  -----------------           -----         -----          ---
  Google Sites                 65.4%        65.5%          0.1
  ------------                 ----         ----           ---
  Yahoo! Sites                 17.0%        16.8%         -0.2
  ------------                 ----         ----          ----
  Microsoft Sites              11.3%        11.5%          0.2
  ---------------              ----         ----           ---
  Ask Network                   3.8%         3.7%         -0.1
  -----------                   ---          ---          ----
  AOL LLC Network               2.5%         2.5%          0.0
  ---------------               ---          ---           ---

Americans conducted 14.5 billion searches in February, down 5 percent from January. Google Sites accounted for 9.5 billion searches, followed by Yahoo! Sites (2.4 billion), Microsoft Sites (1.7 billion), Ask Network (540 million) and AOL LLC (358 million).

  comScore Core Search Report*
  February 2010 vs. January 2010
  Total U.S. - Home/Work/University Locations
  Source: comScore qSearch
  ------------------------
                                    Search Queries (MM)
                                   -------------------
                                                        Percent
                                                         Change
                                                        Feb-10 vs.
  Core Search Entity         Jan-10       Feb-10          Jan-10
  ------------------         ------       ------        ----------
  Total Core Search          15,167       14,472            -5%
  -----------------          ------       ------           ---
  Google Sites                9,920        9,475            -4%
  ------------                -----        -----           ---
  Yahoo! Sites                2,583        2,433            -6%
  ------------                -----        -----           ---
  Microsoft Sites             1,715        1,667            -3%
  ---------------             -----        -----           ---
  Ask Network                   574          540            -6%
  -----------                   ---          ---           ---
  AOL LLC                       375          358            -5%
  -------                       ---          ---           ---

* Based on the five major search engines including partner searches and cross-channel 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 the core search numbers.

February 2010 U.S. Expanded Search Rankings

In the February analysis of the top properties where search activity is observed, Google Sites led the search market with 13.5 billion search queries, followed by Yahoo! Sites with 2.5 billion queries and Microsoft Sites with 1.7 billion. Facebook.com experienced significant growth during the month with a 10-percent increase to 436 million searches, while craigslist, inc. jumped one position to #5 with 629 million searches.

  comScore Expanded Search Query Report
  February 2010 vs. January 2010
  Total U.S. - Home/Work/University Locations
  Source: comScore qSearch
  ------------------------
                                        Search Queries (MM)
                                        -------------------
                                                              Percent
                                                              Change
                                                              Feb-10 vs.
  Expanded Search Entity           Jan-10       Feb-10         Jan-10
  ----------------------           ------       ------       ---------
  Total Internet                   23,163       22,271          -4%
  --------------                   ------       ------         ---
  Google Sites                     14,045       13,482          -4%
  ------------                     ------       ------         ---
      Google                       10,378        9,929          -4%
      ------                       ------        -----         ---
      YouTube/All Other             3,667        3,553          -3%
      -----------------             -----        -----         ---
  Yahoo! Sites                      2,670        2,509          -6%
  ------------                      -----        -----         ---
      Yahoo!                        2,647        2,496          -6%
      ------                        -----        -----         ---
      All Other                        23           13         -43%
      ---------                       ---          ---         ---
  Microsoft Sites                   1,772        1,720          -3%
  ---------------                   -----        -----         ---
      Bing                          1,549        1,498          -3%
      ----                          -----        -----         ---
      Microsoft/All Other             223          222           0%
      -------------------             ---          ---         ---
  Ask Network                         736          689          -6%
  -----------                         ---          ---         ---
      ASK.COM                         336          300         -11%
      -------                         ---          ---         ---
      MyWebSearch.com/ All
       Other                          400          389          -3%
      --------------------            ---          ---         ---
  craigslist, inc.                    636          629          -1%
  ----------------                    ---          ---         ---
  eBay                                659          624          -5%
  ----                                ---          ---         ---
  AOL LLC                             576          549          -5%
  -------                             ---          ---         ---
      AOL Search Network              317          299          -6%
      ------------------              ---          ---         ---
      MapQuest/All Other              259          250          -3%
      ------------------              ---          ---         ---
  Facebook.com                        395          436          10%
  ------------                        ---          ---         ---
  Fox Interactive Media               403          391          -3%
  ---------------------               ---          ---         ---
      MySpace                         398          388          -3%
      -------                         ---          ---         ---
      All Other                         5            3         -40%
      ---------                       ---          ---         ---
  Amazon Sites                        238          210         -12%
  ------------                        ---          ---         ---