What is Ad Inventory?

Ad Inventory or Advertising Inventory is a term that describes the advertising space that each publisher has, and which advertisers can buy to host their ads. This can be website, mobile, app or video space. While typically used in online advertising, ad inventory can also define a publisher’s ad space in print or other media.

Ad inventory is typically valued on the basis of impressions – that is, the traffic that a publisher can provide the advertiser with. With the rise of new technologies, ad inventory is increasingly being sold programmatically, through ad exchanges and RTB (real-time bidding).

The ad space is divided among four separate categories: premium guaranteed, audience targeted, remnant, and sponsorships. They all have their different approaches to audience targeting and ad placement.

Ad inventory varies in quality according to a number of impressions than an advertiser can get from the publisher’s ad space, and the positioning of their ad (most notably: above or below the fold).

The cost of ad inventory can be calculated through a variety of models. Publishers can charge advertisers based on the number of leads who’ve performed meaningful actions such as signing up for a newsletter or buying a product (CPA), thousand impressions (CPM), or cost per click (CPC).