When a viewer reaches an ad break in a CTV app, the app signals its SSP that an ad opportunity is available. The SSP packages impression data — device type, content metadata, audience signals (IP address, device IFA), floor price — into an OpenRTB bid request and sends it simultaneously to connected DSPs. Each DSP evaluates the request against its active campaigns, calculates a bid, and responds within the auction window (150–200ms for CTV).
The SSP collects all responses, runs the auction, selects the winning bid, and returns the VAST URL for the winning creative to the CTV app. The app plays the ad. The whole cycle happens in under 200ms — before the viewer would notice any delay.
Key differences from web RTB:
- No cookies: CTV uses device IFA (Identifier for Advertisers) and IP address for audience identification. No browser cookies.
- No clicks: Conversion tracking uses view-through attribution rather than click-based attribution.
- First-price auctions: In India, all major CTV publishers run first-price auctions. You pay your exact bid, not second price. Bid shading (deliberately bidding below perceived value) is used by sophisticated buyers to avoid overpaying.
- Pod auctions: Some publishers auction all ad slots in a break simultaneously (pod bidding) rather than slot-by-slot. This is not yet universal in India CTV.
Related questions
For a full technical breakdown, see the RTB in CTV knowledge base article.