Msg#: 4408845 posted 6:09 am on Jan 21, 2012 (gmt 0)
There's only one thing I've read that might be relevant, and I'm not sure it's relevant to your situation. Google does maintain three different sets of "mobile" results - one each for feature phones, smartphones and tablets.
However, those are very big swings in the numbers you're seeiong. Does make you wonder what's going on.
Msg#: 4408845 posted 1:09 pm on Jan 23, 2012 (gmt 0)
Where did you read they have three different sets of results?
They have a separate mobile index for feature phones, but not until recently did they create a googlebot for smartphones. As far as I know, the index for smartphones, tablets and desktop users are the same - but feature phones have their own index.