Horace, in his understated way of saying things, talks about iOS app downloads:
“Growth like this is hard to get one’s mind around. Not only are downloads increasing, but the rate of increase is increasing.”
His chart where he compares app downloads to music downloads in the iTunes store helps. The iTunes store became the biggest music retailer in less than 5 years after initially opening, displacing Best Buy and Wal-mart. Note the speed of getting to 10 billion downloads:
Personally, I have 223* apps in iTunes, and there are three iOS devices in our house. Doing the math, I get 74 app downloads per device.
* After a one-time attempt to vainly delete the unused ones.