I always get a laugh out of people who get excited about this, I think the far more interesting statistic would be stickiness factors - once you are on a phone platform, how likely are you to stay. For example, what percentage of people get an iPhone and then when their 2 year contract expires - get another iPhone because they love it (despite AT&T). It is hard to judge Android in that context right now because for all the noise it has made in the past year it is still relatively new in the scope of phone devices and carrier contracts. I think RIM has been pretty strong historically in this kind of metric and iPhone has proven well here too.