Based on a recent survey of iPhone users within the AdMob network, the company found the following attitudes and behavior regarding apps discovery and downloads (I don't know the sample size). I'm going to assume that these results are fairly representative of the larger iPhone user population.

Most people are downloading between 1-6 apps per month. They're using 4-6 apps on a weekly basis, but a substantial number are using between 7-10. The inference I draw from this is users have limited attention. While there may be 30 or 40 (or more) apps on users' iPhones, they're only going to use a number that can fit on the home screen.

What the slide above shows is that the top methods for discovering apps are:

1. Searching for a specific type of app
2. Browsing through top app store rankings
3. Word of mouth
4. Ads on other iPhone apps
5. News article/blogs
6. Brand introduces app

The final two slides show that most respondents have downloaded branded apps and that users (60%) are favorably disposed toward them. Indeed, apps are proving to be a very effective tool for brands. We can expect more and more growth among branded apps.