This is good news for someone like me, who avoid buying incomplete used games because they can be hard to trade in for other games after I'm finished with them. Part of the lure of buying online is convenience and cheaper prices (when you can compare different merchants before buying), but it's touch-and-go when it comes to receiving the games. I've gotten some pretty worn games before this way, so any guarantee by a reputable seller that the game is complete and works will go a long way with me.
That said, I'm also hoping to get older and hard to find titles for reasonable prices (but of course, I also don't expect to see hard-to-find collectables like Ikaruga on the DC for $10 shipped). The new blockbuster releases are everywhere, so it would be great to see rarer titles too.
Examples of games I would like to see include: Class of Heroes (PSP), Valkyrie Chronicles (PS3), Marvel vs Capcom 2 (Xbox), Ace Combat 6 (Xbox 360)... Yes, I play all genres of games!