[jsnell]

Where are you getting the 50M/month number from? The latest number reported by Google (Eric Schmidt at a MWC keynote this week) was 350k a day, which would be about 10 million a month.

(Though you are right in that given the kind of growth the smartphone market is going through, installed base is quickly going to be irrelevant and what matters is new sales).

[pyre]

New sales will only matter up to a certain point. Once the market is saturated you can't tell if a new sale is someone newly adopting your platform, or just someone that is moving from one phone to another while remaining on your platform.

[borism]

you can't tell if a new sale is someone newly adopting your platform, or just someone that is moving from one phone to another while remaining on your platform

I'm sure Google or Apple can tell, since activating Android or iOS involves linking it with Google or iTunes account.

[pyre]

But new sales are usually numbers in terms of new phones that people bought, not numbers on how many of them just activated their phone for the first time. Buying your phone is a sale. Activating your iOS or Google account is not.