I am dying to know it. Maybe something in its name or logo...
closed as primarily opinion-based by kiamlaluno♦ Jan 1 '15 at 6:10
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.
You would need to ask the people who are choosing which sites to spam for their motivation, to get any sort of realistic answer.
We can't tell you here, unfortunately, we simply don't know who these spammers are, never mind why they may or may not choose to spam one site over another.
Maybe they like blue things. Maybe they like things starting with the letter 'D'. Who knows :)