[wlesieutre]

Unit market share is useful for some things, revenue market share is useful for others. If you wanted to talk about how solid iMessage is as a platform, maybe for the relative value of selling sticker packs and other iMessage tie-ins designed for the Indian market versus doing something cross platform or on Android, you might be interested in knowing how many users there are in each camp.

On the other hand, the people buying $20 phones might be less likely to spend $1 on your app than the people buying $300 phones, so unit market share doesn't tell the whole story either.

Any attempt to boil the whole thing down to one number is going to have shortcomings, but it's still useful to look at the numbers as long as you keep them in mind.