While iPhone is only about 3% of the handset penetration it is responsible for a huge amounts of activity

• 1.3B Internet users
• 1.8B Fixed line telephones
• 2.9B Mobile Phones
• 4B Mobile users

But out of  4B mobile users there are only 40M iPhones (inc about 20M iPod touch). Howver these 40M  have downloaded 2B apps from the app store. I looked at mine and i have 142, which was a bit if a shock and shows i was above the avergae amount of apps downloaded.  take a look at an app store statistics article here.