Sadly it looks like all or even most signature campaigns will be gone in a few months they are slowly dying off which is unfortunate I would of loved to get in on one.
There is no reason to believe that. They come and go, and I remember there being fewer and worse paid campaigns in the past. What is mostly gone is the pay per post model some followed.
Yeh this isn't really true. The campaigns will always come and go unless the forum bans them. I heard PrimeDice will probably be back with a new campaign soon anyway, though they'll probably limit it to seniors and above I think.