Just a couple of days ago, I discovered that Google is analyzing Android address books to target advertising at the device's owner (see here). Now I discovered the next thing.
Again, in the Play store, I noticed something interesting: There were some music tracks with a recommendation saying "Popular with LeAnn Rimes listeners".
I do have music of LeAnn Rimes on my tablet, which I listen to every once in a while. However, I didn't buy it in the Play store. I copied the tracks from a CD which I bought in a normal CD store to my computer (which is legal in my homecountry Germany) and moved them to the tablet after I bought it. I also never searched for LeAnn Rimes on Google search. The music player I use is Apollo which is included in the CyanogenMod Android distribution - so no Google product. Of course, I also disabled the usage statistics and cover download functions in Apollo, but it anyway would transmit the data not to Google but to the Apollo team.
So again, the only way how Google could have found out that I listen to LeAnn Rimes, would be if some Google app had scanned and analyzed my tablet, which is illegal as computer espionage.