Paying people to leave comments on your posts (bounties, etc) is not a good idea in my opinion.

I think it's better to use money on advertising of some kind. Paying for ads is a reasonable way to drive traffic to a piece of content -- and then if the metric of "number of comments per post" goes up, that shows it's working. But if you pay for people to leave comments, that is not organic engagement (it's the opposite) and in my opinion organic engagement is much more valuable.

I just don't see much of a difference between "bounties for comments" and buying fake followers. It's the same kind of formula. People are free to do that if they want.

It depends on the goal. If the goal is to have fun and talk to people on steem then sure bounties are fine. but if the goal is to make money or build a business, paying bounties for people to comment is a big mistake in my opinion.