Google outmonetise - how do you know that - they won't tell you the percetnage of the clickthrough nor the price of the click in the first place
Seekport - if it's a blended Infospace feed then you are taking a cut of a cut...
MIVA - they have quite low bid values in UK and in US I know they also have low bids - there's a lot of suspect traffic coming via their partners so many advertisers wary
IMHO you have two options if you have traffic:
Google or Overture
For a google syndication (not adsense) you either have to have traffic or know someone that can open the door.
For Overture - exactly the same....
Believe me they are worth it to have as your feed - but again you will have to jump through hoops.
Without traffic it pains me to say either YPN or Adsense would your best options for a reasonable payout. At least they have a very very wide range of subject areas covered - which other feeds may not.