Media buyers operating in the online space already know about advertising exchanges. For the mere mortals in account service or creative, the concept is a bit fuzzier. But thanks to The New York Times, ad exchanges are coming into focus.
Big publishers try to sell Web site advertising space through their sales forces at high prices. Most cannot sell all their inventory, so they send the leftover, or “remnant,” space to an ad network or to an ad exchange.
Ad networks and ad exchanges are both in the business of selling remnant inventory, but they do it in slightly different ways. The networks, which function as middlemen, sell chunks of inventory through their sales forces, which can simplify the buying process for advertisers.
Exchanges, on the other hand, let advertisers buy ads directly, and place them one by one. Because there are usually lower fees, buying off exchanges tends to be cheaper — though more labor-intensive — than buying through networks.