comScore released their January 2009 report on search market share, and for the first time in a while, Google’s share declined month to month.

In December 2008, Google had a 63.5 % share, but in January, they dropped down to a 63.0% share. Yahoo gained month to month with a gain from 20.5% to 21.0%.

In any event, you need to understand this is month to month and you need to look at the numbers over time. So I wouldn’t jump to any conclusions after looking at the monthly numbers.

A WebmasterWorld thread is discussing this and one member said something very funny, as to a possible explanation:

Could be… They go to Google, do a search on that Saturday and freak out and leave. Then they head over to #2, Yahoo.

Forum discussion at WebmasterWorld.