Inventory

Also known as: ad inventory, ad space

Ad inventory refers to all available ad space on a given site. The terms "inventory" and "ad space" are often used interchangeably in the industry.

Inventory is typically divided into three categories:

Premium inventory: The most valuable tier, drawn from recognizable publishers, high-traffic pages, and highly visible placements on a webpage. Premium inventory is usually sold directly to advertisers at or above a publisher's standard rate.

Remnant inventory: Ad space that goes unsold through direct deals and other primary monetization channels. Remnant inventory is typically offloaded at a lower price than the publisher's standard rate, often through ad networks or exchanges.

Long-tail inventory: Ad space on low-traffic sites and blogs. Google AdSense is the dominant ad exchange serving this segment, though publishers seeking stronger monetization alternatives may turn to affiliate programs or other ad networks.