I'll second this. I'm an avid gamer. Between my Wii, Xbox, PS3, and PC I probably have AT LEAST 500 games. Steam alone has ~150, Impulse ~50, disc-based games (and floppy before) make up the rest. I still have some old SNES (I lost my NES and Atari years ago, somehow only my SNES survived to my adulthood).
That said, I pirate games. Alot. As in, I pirated probably at least 1/2 of my steam collection, and just about every other PC game I own. Why? Because the demos honestly suck. One tutorial level and maybe a random campaign mission? Yea, right.
I pirate it, play it through (If I even get that far, most games don't make it past the 2nd-3rd area/mission), maybe do a skirmish or so to see how well the game balance is, and if I liked it, I buy it. Not just "Oh, I see it's on the bargain bin now for $5" buy it, I mean "Oh, this just came out this week, I pirated and liked it, so here's $50-70, good job guys" buy it. They're not only NOT losing sales due to my piracy, they're GAINING sales.
For instance, I pirated this one RTS game a year or so ago, played a couple campaign missions, did a skirmish. I really liked it, and bought it. At the same time, I gave my friends (Who I regularly game with) copies of the game and told them if they liked it, to buy it and we'd all play together. Not only did I manage to convince them to buy the game, but we all also bought the expansions.
Now, I know that there's only anecdotal evidence here, but what I'm saying is that the game company got $350 ($70 each for game + exp * 5) because I pirated the game, rather than $0 if I hadn't. I just wouldn't have really bothered with it unless it really caught my eye somehow, and I definitely wouldn't have talked a few friends into buying copies.
Conversely, this new DRM stuff (Tages, Starforce, etc) is so obnoxious, I just won't even bother pirating the games, because I won't be buying them. I simply don't have enough time to play ALL the games out there, so I really don't mind too much if I miss out on one or two titles - even if I was looking forward to them, as was the case with anno 1404. TAGES? Blah, not even a pirate from me. Sad that I couldn't play it? Sorta. I've looked at videos and it's just a rehash of the previous games. Nothing really new to see here, moving on.. :)