I'm not convinced by the official figures of how much is supposedly lost through piracy.
The figures all assume that everyone who pirated the game would have bought it otherwise. And that is a stretch. A very big stretch.
I'd be genuinely surprised if more than 1/4 would actually have bought the game.
The GTA titles might have been fairly large but they're still distributed through the internet, in practice it's still a DLC.
As for those sports and FPS titles, gamers need to refuse to buy them. If people just keep pouring money into half-assed games the developers will just make them more and more half-assed with every new version. Loss of sales is the only thing that makes developers change their ways.
EA learned a huge lesson with Pro Street, people hated it so they tried something different. When no one bought that one they made drastic changes to how they developed their NFS titles. Now we have Shift, which according to IGN is one of if not the best NFS title ever.
Madden NFL is the 7th best selling video game franchise and Madden 10, the one which you need to buy DLC's to make work correctly, sold more than any other year's installment.
Unfortunately, by-and-large gamers aren't the experienced and savvy sort (ie: haven't been playing games for 20 years, even the older console gamers are relatively new to gaming) so don't realize the huge ripoff incumbent in DLC's.
This also accounts for the vast majority of gamers accepting second-rate games as being somehow tremendous achievements (à la MW2).