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It's also quite possible that the users lost from imposing such a rule end up costing the dapp more than the value of their vote.
Lot's of weird edge-cases to consider.

Would be a mess. But I can see people naturally and voluntarily supporting the brands they use. People already do that. Promotes healthy competition. If it fails to meet expectations the business loses more than just a few customers.

Much more likely that some kind of bonus would be issued to those that upvote the witness.
(Rather than forcing the vote)
People are more likely to respond positively to positive reinforcement.
Like maybe you get to mint a free NFT or something.
Of course it has to be based on vote strength to avoid Sybil attack.
Devil is in the Details.