If they pay more than others, they can attract the best users like what ChipMixer is doing.
This is not the reason why Chipmixer has some of the best posters on the forum--it's because DarkStar_ runs a very tight and mechanically sound ship. He's extremely selective when looking at applicants and even goes for the most trusted members in addition to a history of quality posts. If everyone ran their campaign like him, there wouldn't be any issues (and there probably wouldn't be enough members to fill all the slots, either). Nothing against good managers like Yahoo62278 and Hhampuz and a handful of others, but there's a reason why the Chipmixer campaign is considered elite.
What if Yobit change the maximum posts to 40 per day? I think there should be a rule regarding maximum number of eligible posts.
I'll agree with you there, but I don't think Theymos would implement any regulations like that. If Yobit actually pulled some crap like that, however, he would probably nuke the campaign just like he did the last time. With hundreds of members making 40 posts per day, you know the forum would turn into a snake's nest within hours.
This, just like the "minimum wage" suggestion a while ago, is unenforceable without some seriously Orwellian policing and I don't think there is any interest among forum administration to get involved in that.
I don't think so either--and as supporting evidence, Theymos has never put into effect any such rules for signature campaigns (that I'm aware of). Him halting the Yobit campaign last time and temp-banning some of the shitposters in it was actually a surprise to me.
Likely it wouldn't even solve the problem. Campaigns that pay pennies for shitposts could still pay pennies for shitposts, just hire more shitposters / account farmers / etc.
That "pennies" thing just isn't true, though. Even if a campaign pays a few thousand sats per post, it adds up pretty quickly. These things are extremely lucrative, especially if a participant is living in a poor country with high unemployment. It's no wonder there are so many applicants as soon as a new campaign pops up.