http://www.computerandvideogames.com/33 ... -says-dev/

First of all, used/borrowed/rented games are how many consumers find out your product even exists!

A lot of those consumers are actually children whose parents aren't about to spend £40 on something that could wind up just sitting on a shelf, and especially when they had doubts about the content to begin with...

Secondly, increasingly games are only given the minimum of testing, it's blatantly obvious now. Or quite a large percentage of the game is sold to you as DLC. Or even worse, you're sold something that unlocks what's already on the disc

Thirdly, if the bricks and mortar stores go out of business (see the state of GAME, HMV, GameStop etc), do you honestly think all those people will suddenly start queuing in the supermarket just for a game? But hey, maybe they'll spend all day downloading it. After the 'day one patch', of course