In online advertising, advertisers bid to buy opportunities to advertise, called ad calls, from publishers. In addition, third party data providers may use side information to label some ad calls, indicating those ad calls offer greater value to some advertisers. Those advertisers may bid more for labeled ad calls, purchasing a combination of information from data providers and ad calls from publishers.

This raises some interesting questions: How should revenue be divided between data providers and publishers? Should higher reserve prices apply to better-informed buyers? How should a market that includes side information be structured to encourage participation from buyers, sellers, and information providers?