Here's the fact: a pirate won't buy your game, even if you've created the first truly unbreakable DRM and your game scored a 100 on metacritic, they'll just ignore it and look for the next one.
I was thinking about writing a lot more, but everything I had to say was said already. But here's a quick recap:
1)Pirates will play your(the publisher's) game before those who bought it.
2)DRM is a waste of money, and you're not making the pirates' lifes any harder. Actually, only those who buy the game are being punished by your DRM.
3)Many DRM methdos where broken THOUSANDS of times, and I'm not exagerating.
4)The internet, specially the torrent network, is an eternal repository for your games and for cracks to make them playable, that's why I'm not worried about your servers going down.
5)Publisher's are becoming villains, crackers are becoming heroes.
I guess this pretty much sums the facts. And just to make it clear: I'm against piracy, and the ONLY reason I buy games is to support the developers(and to play, of course).