Bloomberg reports that Yahoo has gained search share in September 2008 while Microsoft has lost some of its share.

Some feel that Yahoo’s numbers are grossly miscalculated; one forum member has never seen more than 13% of Yahoo visitors and thinks that comScore’s assessment isn’t correct. However, pageoneresults notes that Hitwise also does a similar calculation with Yahoo at 18.06% for September. That said, the data is said to be based on “speculative algorithms.”

I would argue that different users use different search engines. Maybe they aren’t searching for your site/product.

Forum discussion continues at WebmasterWorld and DigitalPoint Forums