Glossary/Programmatic/Google Ad Manager
What is Google Ad Manager and how do publishers use it?
What Google Ad Manager does for publishers, how it decides which ad to show, and how to bring your own audience data into it.
Written by Samhub with the help of AI·Updated 13 Oct 2026·3 min readGoogle Ad Manager (GAM) is Google’s platform for publishers to manage and sell ad space. It combines an ad server, which runs direct campaigns, with an ad exchange for programmatic demand.
What it does
| Part | Job |
|---|---|
| Ad server | Books, targets and delivers direct campaigns |
| Ad exchange | Sells impressions to programmatic buyers |
| Reporting | Impressions, revenue and delivery per campaign |
| Key values | Custom targeting such as section or audience |
How it chooses an ad
Page requests an ad
With size, page and key values.
Direct campaigns compete
Based on priority and delivery goals.
Programmatic bids compete
From Google’s exchange and header bidding.
The best option wins
And the impression is counted.
16 pages for publishers, with a checklist for data, programmatic and direct sales.
Add your own audience data
Audiences can be passed to GAM as key values, so both direct campaigns and programmatic deals can target them. That turns the same ad server into a tool for selling your own data.
CPM uplift at Stampen Media after activating first-party audiences with Samhub.
Frequently asked questions
There is a free version for smaller publishers and a paid version, Ad Manager 360, for larger ones.
It combines DoubleClick for Publishers and DoubleClick Ad Exchange, merged in 2018.
Yes, Prebid is often set up to compete inside GAM.
You need an ad server. GAM is the most common one, but there are alternatives.
Related terms
Decides which ad to show and counts the results.
A marketplace where ad impressions are auctioned.
Lets many buyers bid at once before the ad server decides.
The team that sets up, runs and reports campaigns.
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.
