The last solution you mentioned was one I ended up implementing but I just wasn't happy enough with the rest of the solution to work out better fraud detection.

The last solution you mentioned was one I ended up implementing but I just wasn't happy enough with the rest of the solution to work out better fraud detection. One other suggestion for going forward might be to implement none software bounties as well. A large portion of my development was based on the idea of community bounties. Say Bountyville wants their park cleaned up so their kids can play they all chip into a bounty on your site. Receive proposals from companies then choose the best one to do the job. This would help you get more "normal" people involved in the site which might translate into these people discovering the software side of the site as well. The only difference you need for those are a two stage voting process where by users vote on proposals before the action and also on the result after. Anyhow, best of luck.