The hoarding and collecting impulse is deep in the gamer heart, driving us to get that last achievement or finish out a dungeon, character, or game after it has stopped being fun. One tool I like for reducing my meatspace clutter is having an online distribution channel. As long as I can trust them to stay in business and available, an archive somewhere will hold my stuff. All the things that can happen to your physical copies no longer matter, from losing them in the move or house to soda and pet messes to figuring out how to read 3.5″ floppies these days. Someone out there, with better backup practices than me, will let me download a copy if I ever need them again.
The same applies to the Steam Cloud and my saved games. Horrible things happen to my computer more often than they happen to my Steam access.
I had not explored Battle.net before StarCraft II. They have a place to input your keys for Blizzard games. Conveniently, I still have every CD and every key; I am best situated to use the service because I do not need it (irony). But I do not need to bring my CDs to LAN parties “just in case.” I need this service for all my old games, so I can input a code and stop hoarding physical media, although I am likely to keep and protect my Master of Orion CD and manual forever.