The thing with modern PC demos is that they're generally 800+ megs to download, and with a budget internet connection, its a very time consuming thing, on top of that the demo only lasts say 15 minutes.

Just earlier today, I downloaded a game called Armor Heros or something for XBLA, and the demo was over as soon as I ran out of ammo. I only started with 150 gattling rounds. 800 megs. Done with in less than 5 minutes.

Quite frankly, demos are starting to be a waste of time.