I'm sure there are users who post more often than that in the gambling section for their own gratification.
Absolutely, and many are good contributors.
I can't see myself ever going for a gambling campaign simply because I have less than nothing to say on the subject. More power to those who can.
When I was invited by the campaign manager to join the Sportsbet.io campaign I had my reservations because I don't gamble, and felt the same way. I rarely ventured into the gambling sections, never posted there. The campaign manager told me he was aware of my post history, and the requirement to post in the gambling boards doesn't apply in my case.
But, being the guy I am, I went venturing into the gambling section anyway, and before long found myself talking about sports which I enjoy following. I've found many users who's posts I've enjoyed in other sections of the forum, and they make equally good posts in the gambling boards as well. I've had good time discussing my favorite sports team as they made their way to the championship game, which wasn't something I expected.
As for the campaign mentioned in the OP, yeah great pay rates, but it's not for me.