Remnant Ad Inventory (also known as Backfill)
Advertising inventory that a publisher has failed to sell using its direct sales force or has decided not to use its direct sales force to sell this particular ad inventory or class of ad inventory. The publishers’ remnant ad inventory is then redirected to third parties to sell on their behalf. In many cases the publisher requires the identity of the publisher or title for the ad inventory not to be disclosed so the marketer has to buy the ad inventory blind. This is done by publishers to avoid gaming by marketers that could adversely impact the pricing of direct sold ad inventory. However, some publishers are experimenting with direct selling remnant ad inventory themselves through their own branded often by invitation only private ad exchanges. In a private ad exchange the publisher has more control over what ad inventory gets sold to whom and to decide which bids to accept. In addition, publishers are finding private ad exchanges are valuable sources of market intelligence allowing them to track and evaluate media buyers bidding behavior and ad inventory needs.