Earlier quoted context omitted.
Indeed. Fragmentation is probably the biggest reason we'll never see Android Market-sales on a per-device basis top what each iPhone user spends in the App Store- there's a wife range of CPU power, RAM, graphics capability, peripherals, multitouch or not, etc on Android devices. Like being back in the world of Windows CE...
The same is happening to the iPhone ecosystem; at a slower pace, but it's happening. Before it was the iPhone 2G; now it's iPhone 2G, 3G, 3GS, iPad, soon the new iPhone 4G... soon there will be way too many differences in resolution, screen size, CPU and OS too. Sales per-device is irrelevant, IMO. If I sell 100 for 10 devices, it's better than selling 90 for 3 devices. It's not like I have to add one IF() condition…
Usage stats from my app in April (somewhat unscientific but illustrates my point decently): iPhone 3G: 49 users iPhone 3GS: 48 users iPod Touch 2nd Gen 4 users iPod Touch 1st Gen 3 users iPhone Edge 2 users iPod touch 1 user iPad 1 user (might have been me...)