Before I knew to check the review websites when buying a game, I always just bought whatever games that I thought looked the “coolest”… and therefore was literally just judging a book, err… video-game…, by its cover.
I think that one of the main reasons that stores like GameStop can thrive is that you simply can't return most of the merchandise if it's been opened. The reality is that physical copies of a video-game cost almost nothing to produce, and are then sold at $50-$60 USD a piece!
If you're making lousy video games, then you deserve to eat the cost of the disc if people really don't want to keep it for more than a day or two. Okay, yes I know that this could be damaging to the industry overall, but it would definitely filter out a lot of the crud on the market that people end up with that's simply not a good value compared to other titles at that same price point.
/end-rant