The study seems to apply to situational sadness more than the generalized variety;when it was conducted, "the researchers randomly assigned people to either watch a sad video or an emotionally neutral video, after which they were asked to purchase a commodity (i.e. bottle of water). Participants in the sad group offered about 300% more than the neutral group for the same item."
So next time you go see a tearjerker, hands off the wallet as you leave the theater - or you could end up crying into a $7 bucket of popcorn.

Don't be like Dawson.