Cost per account opening cut by 49%

A fintech app on iOS and Android. The action that matters — opening an account — happens days after the install: after sign-up, verification and a first deposit. The ad platforms could see installs, but not which of them turned into customers, so campaigns were optimising for cheap installs rather than accounts.

We built a server-side attribution chain: app events go to AppsFlyer, from there through server-side GTM into the Meta Conversions API. Opening an account became an event the ad account receives as reliably as an install.

• An event specification for the SDK: what the app sends, when, and with which parameters.
• An unbroken chain from install → sign-up → verification → account, so every opening is tied back to a click.
• Campaign optimisation moved from installs to the account-opening event.

Cost per account opening fell by 49% and ROAS rose 3.2×. 98% of events reach the ad accounts server-side — no losses to ad blockers or iOS restrictions.