DomainSponsor just wrapped-up their WebFest Global conference in California (formerly DomainFest Global). Ron Jackson attended a press breakfast with Debra Domeyer, who reported that "Domeyer made was that the company saw good year over year growth in domain monetization with the average PPC revenue in 4Q-2012 coming in a little better than the same quarter a year earlier."
I have also seen an increase in DomainSponsor income in the past few months. I have also noriced that the domains managed by the mets-parking platform Above are migrating away from other services and toward DomainSponsor. Your mileage may vary, or course, but it may be time to give DomainSponsor a try again.