> Our “popularity” guesstimates are derived from annualized monthly Google queries (from AdWords traffic estimator), and some fuzzy math. It’s not scientific, but it’s better than nothing.

...to be honest, I'm not sure if it really is 'better than nothing' - I don't think Google queries are a good indicator at all of install base, but I guess that's not what they're measuring - rather, the more nebulous 'popularity'. Also, it's going to lead to lots of problems with iPads, which I think you can see by the fact the iPad Mini has a 'popularity' of 2.5%.