With all the hype over app stores (yes, I do believe there is a lot of hype), it’s worth putting a bit of perspective on the size of the marketing compared to other mobile-related activities:

iphone has 35 million users is 0.7% of all phones worldwide and 3.5% of the US market (yes, it has sold 50+ million, but various people are on upgrades so in terms of active users the fiture is lower).
The current value of app sales across ALL handsets was $7 billion in 2009.
The value of MMS (arguably a niche medium) was $28 billion in 2009 (1.4 billion active users).
The global value of SMS? $128 billion (3 billion users).
*figures from Portio

Whilst a lot of media types are running around telling us the future of mobile is in apps, this kind of puts things into perspective really.