1. A method comprising: receiving, over a network, a request for recommended content from a requester, the request comprising a content unit, the content unit being associated with a respective plurality of content sources, each respective content source comprising a respective content recommendation methodology and at least one respective data source, wherein the respective content source identifies links to recommended content items by applying the respective content recommendation methodology to the at least one respective data source; selecting, using a computing device, one content source of the plurality of content sources; identifying, using the computing device, a plurality of links to recommended content items accessible over the network using the one content source of the plurality of content sources; and transmitting, over the network, the plurality of links to recommended content items to the requester.