Netflix just shipped a Conversion API. Here's what that means for the measurement stack.
On March 4, Netflix announced its own CAPI tools as part of a broader Netflix Ads Suite expansion. The API is server-to-server, designed to let advertisers send conversion events directly to Netflix without routing through a browser. Early testing with Tinuiti, the largest independent full-funnel agency in the US, showed campaigns outperforming benchmarks by more than 75% across financial services, ed tech, and retail clients, according to Netflix.
That 75% number is doing a lot of heavy lifting in the press release. Netflix didn't disclose baseline benchmarks, sample sizes, or which specific metrics improved. Take it as directional, not definitive. But the signal is clear: Netflix is building a measurement product, not just an ad product.
Every platform now has a CAPI. That's the story.
Facebook launched the first major Conversion API in 2020. Google followed. Then TikTok, Snap, LinkedIn (which shipped its CAPI last year specifically to help advertisers retarget on CTV). Now Netflix and Roku both have them.
Here's how a CAPI works, step by step:
- An advertiser's server detects a conversion event (purchase, signup, app install)
- The server sends that event directly to the ad platform's API endpoint, server-to-server
- The platform matches the event to an ad exposure using hashed identifiers (typically hashed email, phone, or device ID)
- The platform reports the attributed conversion back to the advertiser
No browser pixel fires. No third-party cookie dependency. No client-side JavaScript that ad blockers or browser restrictions can intercept. The entire data handshake happens between two servers.
This is why every platform has converged on the same architecture. When Apple's ATT gutted mobile signal in 2021 and browsers started restricting third-party cookies, CAPIs became the backup generator for attribution. Now they're the primary power source.
What broke, and what Netflix's CAPI actually fixes
The specific problem for CTV has always been worse than for display or social. There are no tracking pixels on TV screens. People don't click on their Roku remotes to visit a landing page. Traditional web attribution simply does not work in the living room.
Netflix's CAPI addresses this by letting advertisers connect their own first-party conversion data to Netflix's ad platform. If someone watches a Netflix ad for a DTC brand, then purchases from that brand's website two days later, the brand's server can report that purchase to Netflix, and Netflix can attribute it back to the ad exposure.
