I found some slave auction market happening in the second life mostly by BDSM community. I think an illegal slave auction market will bring more rp. There can be a board with registered wanna-be slaves and any citizen can place his money. Finally maybe on weekends slaves be delivered to the bidding winner for a specific timeframe. I don't think factions should handle this kind of stuff 'cause it might discourage other faction members. Maybe business houses like twister can do it after paying sufficient bribe to HPD. Just a suggestion.