Glossary/Programmatic/Ad inventory
What is ad inventory and how do publishers sell it?
What ad inventory is, how publishers forecast and sell it, and how to raise its value.
Written by Samhub with the help of AI·Updated 13 Oct 2026·3 min readAd inventory is the total ad space a publisher has available to sell, usually counted as the number of ad impressions expected over a period.
How inventory is counted
Inventory = page views × ad units per page
Example: 3,000,000 page views × 4 ad units = 12,000,000 impressions
Illustrative numbers.
Where inventory is sold
| Channel | Typical use |
|---|---|
| Direct | Premium placements and audience campaigns |
| Programmatic deals | PMP and programmatic guaranteed |
| Open auction | Remaining impressions |
16 pages for publishers, with a checklist for data, programmatic and direct sales.
Raise the value, not just the volume
More ad units add inventory but can lower prices and hurt reading. Audience data, viewable units and good forecasting raise what each impression earns.
CPM uplift at Stampen Media after activating first-party audiences with Samhub.
Frequently asked questions
Inventory buyers value most, such as visible placements or known audiences.
Inventory left after direct sales, usually sold in auctions.
From traffic history, seasonality and ad units per page, ideally in the ad server.
It earns nothing, which is why fill rate matters.
Related terms
The share of ad requests that get an ad.
The share of available inventory you actually sold.
A space on a page where an ad can appear.
Getting the most revenue from every impression.
The ad space buyers value most.
Ad space left after direct sales.
Samhub audiences let you set higher floors and win more data deals, in every channel you sell.
- A walkthrough with your own data
- Built for publishers and media houses
- 30 minutes, no commitment
Turn your audience data into more revenue
Get the Media Monetization Playbook: how media houses turn first-party data into higher CPMs, data deals and direct sales. With checklists for every step.
