Steam makes buying games quick and simple, it makes installing them and setting them up effortless (The automatic update system? Genius!) it adds features to your game, like the ingame messenger and multiplayer invite system, as well as showing all the relevant news about a game in the library page - All the while protecting the IPs of their vendors.
It's close to perfection, aside from those unfortunate patches and server crashes.
It also exposes everything that's wrong with Games for Windows Live or Ubisoft Online Services Platform. One is efficient and actually offers you a service, the others are just a pointless annoyance.
It is worth noting that both Ubisoft and THQ have recently started cutting their DRM out of games that are directed towards the classical PC audiences - Are they slowly admitting they blew it? Hmmm.