What I don't get is how they didn't make a decent amount of profit on the expansions. They were just new maps, which really shouldn't have been expensive to put together. Sure, You Monster had voice acting too, but it also had a Portal tie-in which again should have boosted sales. If the DLC only broke even too that's quite surprising.
It's a rule they should have learned from Jane Jenson: offer something appealing and easily understandable. Preferably: a game. Have a single goal, with a single target. Add stretch goals once you get near to exceeding it. That's why the PA Kickstarter stressed the 'a year with no ads' thing even though that wasn't really what you were directly funding. The easier to understand, the better you do.