Now my question is this... do you prefer that a casino offer loads of promotions and campaigns and sponsorships and sacrifice RTP in favor of that.... or will you rather have a decent gambling experience with a better RTP?
Personally, I would choose a gambling website that offers the best return-to-player profit for the best possible scenario.
Gambling in itself is already risky- profits are not guaranteed and you suffer absolute loss of the money you wagered if you lost the bet. Assuming that the risk associated in one gambling site that has better RTP is the same with another gambling site that has tons of promotions, then I think it is obvious that you would choose the former.
Better to maximize all the profits since the risks associated with the two are the same. Though marketing in a gambling website gives you the sense of security that they are genuine, again, profits wise, best RTPs still win by a long shot.