Paid re-engagement: retargeting ads that open the app on the thing they promised

Retargeting spend goes to people who have the app but stopped opening it. The ad shows them a specific thing — the item they looked at, the feature they never tried, the content that's new since they left. They tap. The app opens on the home tab. The thing from the ad is somewhere in there. Most lapsed users don't go looking.

What problem does this solve?

A re-engagement click should open the app directly on what the ad showed, with no store visit and no home screen. And the resulting session should attribute to the campaign, so re-engagement spend can be judged on what it produced rather than on impressions.

How do you set the links up?

The re-engagement link carries the destination and the campaign. Because the audience has the app, the link opens it directly; if some of them have uninstalled, the same link handles the store and the deferred landing without a separate creative. The campaign tag ties the session to the ad.

{
  "deepLinkPath": "/collections/new-arrivals",
  "customData": {"cmp": "retarget-lapsed-30d", "cr": "carousel-b", "aud": "lapsed-30"}
}

How is this attributed differently from an install?

• The event is an app open, not an install. It's matched to the click the same way, on a device that already has the app.
• Attribution windows are shorter. A re-engagement click that becomes an open a week later probably isn't the reason for the open.
• On iOS, AdAttributionKit supports re-engagement from 18.4. Earlier versions attribute the open via the link only.
• Cost data joins on the campaign identifier, so re-engagement CPA sits next to acquisition CPA in the same view.

What should the ad promise?

Something specific enough to be a destination. 'Come back' has nowhere to land. 'Your saved items are on sale' lands on saved items. 'New episode of the show you follow' lands on the episode. The creative and the deep link path are the same decision, made once.

Which metric should you watch?

Cost per re-engaged user who did something — a purchase, a session over a minute, a return the next day — not cost per open. Opens are cheap to buy and easy to inflate; the downstream event is what you were paying for.