dug 
Ethan Nicholas, on his iPhone game “iShoot” and why it’s a good idea to make a free version:
Nicholas found some spare time to code a free version of the app--iShoot Lite, which he released in January. Here's how that helped: Inside iShoot Lite he advertised the $3, full version of iShoot. Users downloaded the free version 2.4 million times. And that led 320,000 satisfied iShoot Lite players to pay for iShoot.
(via wired)
Citizen Engineer