Games on demand Service for Xbox Live?

[opurt]

You're buying, not renting. You're getting a full copy of the disc just like you would in the store. You can delete and redownload it whenever you want.

Downsides: You can't sell it when you're done with it. It uses a bunch of disk space (just as much as installing a disc to the hard drive).

Upsides: Won't get scratched. Can't get lost/stolen. Don't have to put a disc in to start playing.