Programmatic advertising: understanding DSP, SSP and RTB

In short: programmatic advertising is the automated buying of ad space, often via real-time auctions. At each page view, a system decides in milliseconds which ad to show, to whom and at what price.

The players in the chain

• DSP (Demand-Side Platform): the advertiser-side platform, buying impressions by criteria (audience, context, budget).
• SSP (Supply-Side Platform): the publisher-side platform, offering its inventory for sale.
• Ad exchange: the marketplace connecting DSP and SSP.
• DMP / data: the data that refines targeting.

RTB (real-time bidding)

In Real-Time Bidding, each impression is auctioned in real time: several advertisers bid, the highest wins the display. It all plays out in milliseconds, at the scale of billions of impressions.

Beyond the open auction

Programmatic isn’t limited to open auctions. There are private deals (PMP) and programmatic guaranteed (guaranteed volume), offering more control and inventory quality — useful for brand safety.

Challenges

• Chain transparency: many intermediaries can reduce the share that actually funds the display.
• Brand safety & fraud: vigilance on inventory quality (MFA sites, invalid traffic).
• Cookieless: targeting shifts to first-party and contextual.

FAQ

Programmatic = display only? No: programmatic extends to video, audio, connected TV and DOOH.

Difference between DSP and SSP? The DSP buys for the advertiser; the SSP sells for the publisher. They meet on the ad exchange.

Is programmatic suitable for small budgets? Yes, it’s accessible, but requires steering (targeting, optimisation, quality control) to be profitable.

PubliCité France — blog, Digital advertising. French version: /blog/publicite-programmatique/