I figured it out!

Well, not really, but it finally hit me. Why do music labels allow paid-for music downloads? Why can I buy movies on iTunes? Why will I be able to buy 360 games on my Xbox soon?

Because it's convenient? Sure.

I think it's because you can't resell these things.

It's not like I can burn the CD of songs I bought on iTunes and resell it. Once these services reach critical mass, companies will be selling everything new. There's no selling any of this stuff used, thus cutting into sales.

Why would I buy a game direct from the Xbox Marketplace for the same price I can get the physical disc? I'll be able to resell the disc to someone else when I'm done with it. I can write off the depreciation as "the cost of playing the game."

I've finally figured it out!