DSP (Demand-Side Platform)

A demand-side platform (DSP) is the buy-side workstation of programmatic ad-tech. Advertisers — or, more commonly, the agency desks that work on their behalf — log into a DSP to load creatives, set audience targeting, set per-impression bid prices, and apply frequency caps. The DSP then bids on behalf of the advertiser into ad exchanges across the open web, CTV, and (since OpenRTB 2.6 added the "dooh" object) programmatic DOOH.

The dominant DSPs in 2026 are The Trade Desk, DV360 (Google), Amazon DSP, and StackAdapt. Each runs a real-time bidding engine that evaluates hundreds of thousands of incoming bid requests per second, applies the advertiser's targeting rules, and returns a bid + creative reference within ~80ms (the RTB timeout budget).

For DOOH specifically, the DSP's job is harder than for web because the bid request describes a shared screen rather than a single user. The targeting layer has to evaluate venue category, time of day, and (where available) sensor-derived audience composition — none of which map cleanly to the cookie-based identity graph the web side of the DSP was built around.

Trillboards exposes a DSP-grade bid endpoint at /support/developers/dsp-api for buyers who want to integrate directly with our supply.