One of the NPC buffoons wandering around the outskirts of town offers you a quest, a really awesome sounding quest involving a rescue, a warlock and loads of loot and experience. It sounds great, but there's a catch. In order to play this quest, you have to pay a little extra real-world cash to unlock it. That's right, you've already bought your game, but did you think you'd get to play through all of it with that meager yield of dough? Well you thought wrong, sucker.
This isn't to say that we don't necessarily like DLC. I don't mind buying expansions to games that I know and love in order to get a little more enjoyment out of it. What we don't like is when the NPC breaks character to try and make a bit more money for the company.
There's a time and a place for everything.