It's worth pointing out that the study in question was on ironic, mystery, or 'literary' short stories acknowledged to be high quality and subjects had to (pretend to) read the works regardless of whether they were spoiled or not.
For works of lesser quality or a different field (say, comedy), those results may not hold. If the only reason to consume a work is to get at the plot payoff, knowing what that payoff is may cause someone to avoid the work. Likewise, timing is a critical part of comedy that spoiling can often ruin.
One other flaw in that study IIRC: they only had subjects read through the stories once. In my experience, many stories can be read profitably twice: once with plot twists unknown to appreciate the mystery and suspense, and a second time (obviously with plot twists known) to appreciate the dramatic irony. The third reading then adds (relatively) little extra.
So if you have a chance to experience fiction spoiler-free, you can get twice as much out of it. But this effect wouldn't be measured in a study where neither group goes through the work twice. You...
The latest SMBC made me laugh a bit, so I thought I'd bring extra LessWrong attention to it.
I don't know if pointing out the subject of the comic in advance will make it more or less funny. Knowing that might be more data regarding that recent study claiming that spoilers don't actually spoil stuff...