It all comes down to the campaign managers and the companies being responsible for their participants..
I think if a paid poster gets banned for spamming then whoever is paying them to do so should recieve a stern warning, meaning the campaign manager and the representetives of the company..
I don't buy into this, it'll be putting too much pressure on the managers, they aren't no AI (LoyceV 😁) to be reviewing every participants post for Plagiarism. Even moderators don't go around the forum searching for plagiarism post and spam for them to review, they work on reported cases. Unless there's an automated system like a bot set in place to handle this, it'll just be a waste of time.
About managers getting punished for the participants posting habit, i think that's fair if the managers are intentionally paying the spammers for their spamming (like Yobit signature campaign). Plagiarism can't be notice that quickly although an offtopic, irrelevant or spam reply can be spotted without any effort so the managers have no excuse in paying for those post, they were employed to manage the campaigns therefore should be responsible in overseeing the affair of the campaign operation on the forum. Unlike the yobit scenario that only the signature ads was affected maybe introducing a punishment for not so serious managers will make a difference.