The email announcing the renewed agreement between Microsoft and Yahoo! for search advertising included the fact that Bing has garnered more than 20% of the desktop search market, so I decided to chart a year's worth of data from comScore.

Mar-14 Apr-14 May-14 Jun-14 Jul-14 Aug-14 Sep-14 Oct-14 Nov-14 Dec-14 Jan-15 Feb-15 Mar-15
Google 67.5% 67.6% 67.6% 67.6% 67.4% 67.3% 67.3% 67.0% 67.0% 65.4% 64.4% 64.5% 64.4%
Microsoft 18.6% 18.7% 18.8% 19.2% 19.3% 19.4% 19.4% 19.5% 19.6% 19.7% 19.7% 19.8% 20.1%
Yahoo 10.1% 10.0% 10.0% 9.8% 10.0% 10.0% 10.0% 10.3% 10.2% 11.8% 13.0% 12.8% 12.7%
Ask 2.5% 2.4% 2.3% 2.1% 2.0% 2.0% 2.0% 1.9% 2.0% 2.0% 1.8% 1.8% 1.8%
AOL 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.2% 1.3% 1.2% 1.1% 1.1% 1.1%

Ask and AOL are likely to continue downward. Google's share of desktop search appears to be eroding, while both Yahoo! and Bing have both shown incremental growth.

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