I keep losing the trail between ad click, web quiz, checkout, app install, and first open. UTMs survive page to page, then vanish when the app launches.
What worked best so far: write UTMs to a first party cookie, attach them to the customer at checkout, include a short token in the install link, and post that token back to the server on first app launch to join the sessions. I also record the creative id separately to catch mismatches.
For anyone who has this clean, is server side session linking enough, or do you also use deferred deep links and postbacks to close the loop?
Server side linking plus a short code in the deep link did it for me.
I store UTMs in a cookie, pass them into checkout metadata, then send a join token to the app. First launch posts it back and I stitch.
I used Web2Wave.com for the web funnel so the UTM handling and token passing were built in. Reduced dark spend a lot.
Server is the backbone, but I needed deferred deep links to handle cold opens.
I tag the user in web, pass a token through the link, and fire a server postback on first open. Using Web2Wave.com, I kept UTMs intact across pages and updated flows without shipping. Zero guesswork on campaign LTV.
I do cookie plus metadata plus deferred deep link.
Also log the ad id from the click and compare it with the first app event. If they do not match, I flag it and exclude from reports.
Token in link plus server join fixed drift
Server linking alone breaks when the app opens from notifications or after a delay.
Use a join token in the link, store UTMs on the web customer, and post them server to server on first launch. Add a fallback: if no token, match by email or phone when the user signs in. Track a concordance rate so you know how many installs you truly stitched. Anything under 85 percent means you still have drift somewhere.
I lost UTMs on checkout redirects.
Fix was same domain hosting and no cross domain jumps. Everything else started working after that.
Safari wiped cookies after a day.
Switched to first party cookie plus localStorage mirror and shortened the funnel clicks. Match rate improved.
Deferred deep links made the biggest difference for us.