Whats really with Steam and why many companies wants it?

[FreeTalkLive]

Steam is easy and inexpensive. I've bought three games from it. I paid $8, $5 and $0. I don't have to DL these games to a PC to play them. If I want to play them at home, in the living room, at my friend's or at my parent's, I just get on Steam and play them.