My suggestion above is actually likely too rough and not very meaningful
Basically there are in theory a set of different options
Burning a % of the entire post payout
Burning a % of the author's share (I vaguely recall people saying that's how beneficiaries work, not sure)
Burning a % of the curators share
The end goal is that you want a system where the sellers on the other end of the transaction aren't making more than honest curation. But if they make less, obviously no one would be selling any votes.
There isn't really a set level of parameters that ensures that the balance here is just right. Imagine if we went with burning 100% of promotion post payouts. It's still possible for everything on trending to be promoted posts, and the harmful effects of that to be completely absorbed by a collapsing Steem price. So as a rough analogy imagine trending is filled with declined payout promotional rubbish, but Steem price is so low (in part because of it) that it only takes $5 to get to the top of trending. That's the result your intuition was guiding you to fight in the case there were excessive declined payout posts on trending in one of your other comments.
A far better general approach is to just not have promotion be part of vote trading that directly involves sellers at all. One way is just bidding $ into the null account and winning ever increasing promotion placements (that obviously could be placed better than a neglected section on their own). But there are literally countless ways promotion can be done that don't involve a direction transaction between stakeholders and promoters and thus won't risk our proof of brain system.
I'm not against promotion, I'm against vote selling for promotion. They're simply just circle jerking rings in disguise economically speaking, and do harm even if they're run at a loss. We keep them in check by offering non harmful alternatives to promote (eg bidding for placement going straight to null), and combating them directly by downvoting posts with bought votes to make them as unprofitable as possible.
My suggestion above is actually likely too rough and not very meaningful
Basically there are in theory a set of different options
The end goal is that you want a system where the sellers on the other end of the transaction aren't making more than honest curation. But if they make less, obviously no one would be selling any votes.
There isn't really a set level of parameters that ensures that the balance here is just right. Imagine if we went with burning 100% of promotion post payouts. It's still possible for everything on trending to be promoted posts, and the harmful effects of that to be completely absorbed by a collapsing Steem price. So as a rough analogy imagine trending is filled with declined payout promotional rubbish, but Steem price is so low (in part because of it) that it only takes $5 to get to the top of trending. That's the result your intuition was guiding you to fight in the case there were excessive declined payout posts on trending in one of your other comments.
A far better general approach is to just not have promotion be part of vote trading that directly involves sellers at all. One way is just bidding $ into the null account and winning ever increasing promotion placements (that obviously could be placed better than a neglected section on their own). But there are literally countless ways promotion can be done that don't involve a direction transaction between stakeholders and promoters and thus won't risk our proof of brain system.
I'm not against promotion, I'm against vote selling for promotion. They're simply just circle jerking rings in disguise economically speaking, and do harm even if they're run at a loss. We keep them in check by offering non harmful alternatives to promote (eg bidding for placement going straight to null), and combating them directly by downvoting posts with bought votes to make them as unprofitable as possible.