An infomediary works as a personal agent on behalf of consumers to help them take control over information gathered about them for use by marketers and advertisers. The concept of the infomediary was first suggested by former McKinsey consultant John Hagel III and former Harvard Business School professor Jeffrey Rayport in their article The Coming Battle for Customer Information. The concept was explored in greater depth in Hagel's book (co-authored with McKinsey partner Marc Singer) Net Worth: Shaping Markets When Customers Make the Rules.