It's actually a not-unheard of trick. Arkham Asylum, for example, would have a failure case about halfway through the game where Batman's cape would fail to open when he jumped down into a deep (plot-required) pit if the game had been pirated. Batman would crash into the ground and die, the users would take to developer forums or the steam forums to complain that they couldn't get past this one section because of a gamebreaking bug, and then the developers would say, "Yes, that's an anti-piracy measure. If you purchase the game, it won't happen".
Another game, Game Developer Tycoon, would run as normal, but as you got further and further along, in-game pirates would pirate all the games you made and your profits would keep on dropping. People came to the developer forums to ask for ways to keep people from pirating their games, because they couldn't make any money because of all of the pirate. The irony was lost on some.
I think the Game Developer Tycoon one is the only actual success story, and that's because the story went viral.
For every person who goes out of their way to complain on the forums, there's probably five that just caution their friends not to buy the game.
I also recall (obviously difficult to verify) accounts from people who claimed that the Arkham Asylum (I recalled it was City...?) bug happened to them with legitimate copies. From a development perspective, an "Easter egg" of that sort requires a LOT of QA effort.
Another game, Game Developer Tycoon, would run as normal, but as you got further and further along, in-game pirates would pirate all the games you made and your profits would keep on dropping. People came to the developer forums to ask for ways to keep people from pirating their games, because they couldn't make any money because of all of the pirate. The irony was lost on some.