Producer/Consumer dilemna: Chicken and Egg?

I am starting to market a new web-based subscription service which needs both producers to maintain their data and consumers of that data. It's creating a chicken/egg scenario since the producers don't want to be maintaining their data if there are no consumers, and the consumers don't want to subscribe if there is no producer's data. How do others market this type of service where both parties are needed simultaneously for the service to work?