Why server-side delivery
Why a browser pixel alone loses conversions, and how sending the same events from Zappush's servers recovers the signal your ads need.
A browser pixel was never built to be reliable. It runs in the shopper's browser, which means anything in that browser can stop it: ad blockers, privacy extensions, strict browser settings, and Apple's tracking limits on iOS. When the pixel is blocked, the conversion simply never reaches Meta. Meta does not know the sale happened, so it optimizes your ads on incomplete data and spends your budget on guesses.
You feel this as ads that "stop working" for no clear reason, reported conversions that trail your real sales, and a match quality score that drifts down. The cause is usually the same: a large share of your conversions never left the browser.
The fix
Server-side delivery sends the same conversions to Meta from Zappush's servers, using Meta's Conversions API rather than the browser alone. Your servers are not affected by an ad blocker or a privacy setting in someone else's browser. So the conversions a browser pixel would have dropped still get through.
This is the difference between Zappush and a plain pixel. The browser pixel still fires when it can. Zappush sends the server-side copy regardless, and Meta reconciles the two so a single sale counts once. You recover the signal the browser loses without double-counting the signal it keeps.
You are not choosing browser or server. You run both. The browser pixel covers what it can, and server-side delivery covers everything it misses.
How it fits together
At a high level, every conversion travels the same path before it reaches your pixel:
- Captured. A shopper's action on your store is recorded as an event, whether or not their browser pixel managed to fire.
- Cleaned and enriched. Zappush tidies the event and attaches the strongest available shopper signals, so the conversion arrives with everything Meta needs to match it well. This is what protects your Event Match Quality.
- Checked. Two guards run before anything goes out. The first makes sure your real store domain is never leaked to Meta, which keeps a restricted-category store compliant. The second makes sure a repeated purchase, such as a shopper refreshing the order-confirmation page, is not counted as a second sale.
- Delivered. The clean, checked conversion is sent to your Meta pixel from Zappush's servers, and the result is tracked so you can confirm it landed.
The result is that your ads optimize on the full picture of what shoppers actually do, not just the slice that survived the browser.
If you advertise in a sensitive category like Health and Wellness, the domain check in step three is doing quiet but important work on every single event, so Meta only ever sees the clean page and never your store's real address.