Shitposters can easily ranked up by buying merit points.
Even if it's not get you banned it's still not accepted by the community. You can try to sell merit just like you can sell your account or trust. If such a transaction gets spotted you'll get negative trust and it will be almost impossible for you to gain merit in future. People will know you and not reward you even if your posts deserves it. So, as you can see it's not worth the trouble in most cases, especially that any user can check your post history, merit and trust ratings.
It's a risky deal. You will pay money for merit that you may not get at all (scammers), or get it and someone finds out and paints you red, or you will get away with it and 6 months later get banned for shitposting and all that time and money goes down the drain.