While media bartering isn’t commonly discussed, the ANA’s two reports on agency transparency referenced the practice 49 times.

Here’s how it works: A barter agency might agree to buy an advertiser’s surplus product, such as an airline’s unsold flight tickets at full price, which it would give to employees for business travel. In return, the airline agrees to invest in a certain amount of media from the agency – often media that the agency acquired at a discount.

Read the full Ad Exchanger article here.