Heard good things about Looksmart but no first hand experience with them yet.
The Prof. is right, Overture and Adwords work, but for me are too arrogant and they have you jumping through hoops just to get/keep listed.
Findwhat and GoClick both work well although traffic is lighter than Overture and Adwords.
Virtually all the rest will waste your money unless they have changed dramatically in the last year. One side note, I did make money with ePilot only because I landed some whales ($10k plus each) with them. Otherwise it would have tanked as well.
7 search also made me a small amount of ROI, but with them I found 2 things very odd:
1) Lots of traffic and low, low conversion. Suspect fraud click thrus
2) More % of winners than other PPC’s. Players from here always seem to do well for some odd reason. Maybe 7 search partners with casino portals or something that attracts good players.
Good luck!
Kevin 11