Most important reason you look for when...
 

promoting a sponsor. Other than exclusive content of course. Tons of FHG's, movie galleries, RSS, etc...???

what do you guys look for?

RSS, and conversion ratios through the roof. :)

what works and what doesnt.

Top of the list is... who the hell is the sponsor? How long have they been in biz and what track record do the principals have?

That is not the end of the "background check" - stupid (read useless) account reps can screw a good sponsor.

After passing the "audit" - then comes what they have to offer...