Before Apple unified the affiliate system for iOS/iTunes Music/Mac App Stores, they had two separate programs based on geography. In order to make the most of the affiliate revenue, you must direct users to the store using the affiliate information for their geography. If you sent the wrong affiliate information for a given request you’d lose out on that commission.
Federated Links was a service to help Mac and iOS developers make more affiliate revenue I built in Fall 2013 / Winter 2014. Federated Links would detect the user’s country and redirect them to the store with the appropriate affiliate parameters, allowing developers link to a single location and not miss out on half of the affiliate commission.
Rather than charge for the service, every 10th access Federated Links would use its own affiliate code rather than the developer’s. Around 6 months after the release of Federated Links, Apple unified the affiliate programs (as it should have been) and Federated Links was shutdown shortly thereafter.
At it’s peak Federated Links was making enough to cover the cost of its server and perhaps a can of cola each month.