nevermind the people who would be flaging people as "bad users" because they were popped in the head by them one too many times.. It's an interesting idea, but a general populus the power to make a user spend more money, with no other gauge then your opinion on them? that's an unfair and very flawed logic.
sticking with a school theme.. being unpopular for many is a very emotionally scarring thing, but it doesn't even have any physical manifest... imaging how different things would be at school if you had to pay money every day based on how popular you are... sure many bullies and jerks would have to pay up, but so would many of those who fly under the radar, or that don't fit in to the various cliques that appear in school, and don't you doubt, if a system like this came about, there would be cliques, or gangs, or clans with a fairly exclusive membership.