Show me your metrics on (1) and (2). It didn't make me more selective because I knew that nothing would happen if I bottomed out. And my part in (2) left me feeling more unvalued than anything this site has ever done.
That's just it, though - Money elicits powerful emotions as a motivator. As a point of commerce people recognize that some things aren't free. This is why people generally gripe about but put up with ads - they recognize that websites have to make money somehow but that's just the cost of doing business. When you tie the money to their behavior on the site, their behavior becomes transactional in nature, not conversational. You can't afford me on a transactional basis. You can't afford anyone. You recognize this by allowing me to buy "boops" or whatever heinous word we're using but not requiring them, which just shows your passive-aggressive desire to make them matter but recognizes your fear in forcing them to matter.