Comment by PowerElectronix

most games make a very good chunk of their lifetime revenue during their first weeks. If you can avoid piracy during that period (through wishlisting, preorders and such) piracy is not going to eat into your revenue significantly.

On the other hand, having strongly anticonsumer DRM will certainly affect sales. If you have a loss of performance or make it too much a hassle (mandatory connections, updates, etc) that will eat into your revenue, and twice as you are paying money to third parties to have consumers be shun away.