We assumed UTMs would survive every redirect. They did not. Our first web funnel lost campaign IDs when the checkout redirected without carrying query strings, and attribution collapsed.
Fixes were simple but easy to miss: persist utm parameters in the session, write them to the user profile at checkout, and tie them to the payment record. That let us trace a paying account back to a specific creative. Once we had that mapping we could optimize creative level ROAS rather than guessing.
Anyone else have a list of fragile places where utms tend to drop out?
We lost utms on mobile redirects and one payment provider that rewrote query strings.
Solution was to read utm from the landing URL and save it server side tied to a temp user id. When checkout completed we attached it to the subscription record. Saved a lot of guesswork.
Some tools or SDKs can output a JSON that maps these fields automatically.
Always capture utm params on first touch and persist them until purchase.
I use hidden fields in checkout and server side mapping to the customer id. That gave us creative level revenue reporting and immediate optimization levers.
Also check redirects from ad networks. Some will drop or rewrite params.
We found utm loss on iOS when using SFSafariView straight to the store.
Workaround was to use a short landing page that captures utm then redirects to store. Easier than debugging every redirect.
Persist utms server side. Do not trust redirects.
Common failure points: third‑party payment pages, app store redirects, and client side navigation that drops query strings. The most robust approach is server side attribution. Capture the utm on first hit, generate a short lived tracking id, and carry that id through checkout. Attach the original utms to the user or order record.
Once you have that, you can join it to your analytics and ad platforms to measure real ROAS and downstream LTV.
We started storing utm in a cookie and also writing it to local storage. That covered both web and webview paths.
Be careful with attribution windows. Map trial starts and revenue back to the original utm to avoid leakage in reporting.
Short term fix is capture utm on first page and include in checkout payload.
Also audit your payment provider redirects. They are common culprits.