Seriously, Ubisoft should set up a Paypal donation link on their site, so people can just go download a cracked version, then pay them anyway.
As in 'Here's your twenty quid, I'm a paying customer, I just don't need to deal with all the bundled shit you're inflicting on me as an honest gamer.'
There's a thread on the Steam Forums, after the Assassin's Creed series went on sale, got to about 600 posts on something like 'post here if you'll buy the game when they remove the idiocy code'.
I'm not saying all 600 would rush out and buy it, but I am damn sure it hurt the sales of the games during the Steam sales, I certainly backed off it. While not all of them would buy it, you have to factor in that only a small proportion of PC gamers use Steam and post on the forums.
Just saying Terraria sold 200,000 copies in a week on sale, how much damage is the DRM doing?
I'm not even saying scrap it, I'm suggesting disable it after a month, or 3-6 months, after 3-6 months most games are getting discounted anyway and the pirates have moved on, the torrents have died down, etc.
IF it keeps the pirates away for a few weeks, great, it's working, but after the early sales period, patch it out and let honest, paying customers own a version nearly as good as the pirated one.