8. The system of claim 7 , wherein the one or more computers are further configured to perform operations comprising: receiving new content for the underserved topic; determining that the new content increases the topic corpus quality measure for the underserved topic; and compensating a provider of the new content based on the increase to the relative topic corpus quality measure.
8. The system of claim 7 , wherein the one or more computers are further configured to perform operations comprising: receiving new content for the underserved topic; determining that the new content increases the topic corpus quality measure for the underserved topic; and compensating a provider of the new content based on the increase to the relative topic corpus quality measure. 9. The system of claim 8 , wherein determining that the new content increases the topic corpus quality measure comprises determining that the new content increases the relevance measure for documents that are included in the topic corpus for the underserved topic.