First off - all it is is Overture redone - and it can be usefull - however - to do affiliate sales you have to have your own landing site (and not just a fpa) - but even then you have to be real careful about the keywords - theyve always been real picky about adult ads
Quite honestly I tried them for a total of 3 years over the time they were Overture and then Yahoo - and they never came close to Google AdWords ROI