The trade show situation, however, is entirely different, however, because the whole thing is purely about marketing. There's no trial product whose real value could be substituted for that marketing.

That said, I'm having trouble with this seeming contradiction:

> Sure, it's unwanted, but _I did sign up for it_.

Maybe "want" is too strong a word, but you certainly knew you were willing to tolerate it when you did sign up for it.

Conversely, when I'm at a trade show, because I find those emails truly unwanted (and actually intolerable from vendors in whom I have no interest), if I've registered with a real e-mail address, I don't share it just for the octopus t-shirt.