In AU apart from reputation there is something called 'Badges'. But I see that no privilege requires a badge nor is it used for placing a bounty or anything else. So why do I need badges for? Is it just for fun? ! Sometimes a user who has lesser reputation has a larger number of badges than the one that has greater reputation. Isn't this contradictory ?
Badges are basically for fun BUT you can tell if someone is active on AU and contributes.
The more gold badges for great answers and the more (silver) guru-badges the more you probably can trust that user to get it correct.
Reputation is more important since you get swag!!