Glossary/Programmatic/Supply-side platform (SSP)
What is an SSP (supply-side platform) for publishers?
What a supply-side platform does for publishers, how it connects your inventory to buyers, and how to get higher prices through your SSPs.
Written by Samhub with the help of AI·Updated 13 Oct 2026·3 min readA supply-side platform (SSP) is software publishers use to sell their ad impressions automatically. It offers each impression to many buyers at once and helps the publisher get the best price.
How an SSP works
An ad slot needs an ad
The page sends an ad request to the SSP, often through header bidding.
The SSP sends bid requests
To DSPs and exchanges, with information about the impression.
Buyers bid
The SSP compares bids against floors and deals.
The best bid wins
The winning ad is returned to the page.
Well-known SSPs
Examples include Google Ad Manager, Magnite, PubMatic and Xandr, and regional SSPs in many markets. Most publishers work with several at once.
16 pages for publishers, with a checklist for data, programmatic and direct sales.
How to get more from your SSPs
Pass audience data
Send privacy-safe audience segments with each impression.
Use deals
Set up PMP deals on your audiences.
Keep names consistent
The same audiences in every SSP, so buyers find them everywhere.
Set smart floors
Per placement and audience, reviewed monthly.
CPM uplift at Stampen Media after activating first-party audiences with Samhub.
Frequently asked questions
The SSP works for the publisher and sells. The DSP works for the advertiser and buys.
They overlap. An exchange runs the auction. Most SSPs today include an exchange.
Enough to create competition for each impression, often three to six, without slowing the page.
Yes, usually a share of the media spend that passes through them.
Related terms
The software advertisers use to buy impressions.
The buy side and sell side of programmatic.
Lets many buyers bid at once before the ad server decides.
Invite-only auctions for premium inventory.
Packaging inventory and data into deals for buyers.
How publishers sell through programmatic.
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.
