It's not a secret, if you want to sell a PC Game, it has to have a multi-player and that multi-player system has to sync up with your central servers somehow.
If you are trying to sell a single player game on PC you might as well not even bother because everyone on the planet will pirate it.
I only play PC for multi-player games and I buy all the multi-player games I play (mostly because they have authentication so you can't pirate them).
If you build a MP game without authentication you are asking to get pirated.
Blizzard built an MP authentication system with Battle.net in 1997. To say that now in 2009, a full PC games developer is not capable of making a MP authentication system is absurd. Valve has it with Steam, Blizzard has it with Battle.net, and most other developers now are just latching on to Steam to do what they can't (apparently?). MW2 requires steam authentication, it shocks me that it is the first non-Valve FPS game I've seen that requires it.

Logged
Pour the wine, hold the grind, quarter to nine, let's go.