> They don't, for instance, collect data on what games I play on my iPhone, because that information is not available to them. they would like to reconstruct t

> They don't, for instance, collect data on what games I play on my iPhone, because that information is not available to them. they would like to reconstruct that information from what they've got, if they could, and they'd probably be more successful than most people would believe if you gave them a zeroth order explanation of "they can't get data outside of their app".