North-star metrics in UK product orgs after the DMA

When a platform gives you less of other people’s data, a single slide still needs a claim. The mistake is to replace missing identifiers with a louder vanity number.

Several Mesh Mapbase clients spent 2024 treating the Digital Markets Act as a rumour and 2025 as a hole in the warehouse. Cross-app graphs that used to look like strategy became, overnight, a sketch. The north-star slide did not get the memo. It still showed a user graph that quietly assumed identifiers you no longer have.

What still belongs on the slide

A north star should be a behaviour you instrument yourselves: first funded action, first listing paid, first clinical appointment booked — whatever the product actually is. It should not be “reach” borrowed from a platform you do not control. After the DMA, borrowed reach is not merely fragile; it is often incomparable with last year, which makes the year-on-year chart a costume.

We ask teams to split the slide. Left: first-party behaviour, with the activation sentence from Cohort Instrumentation. Right: platform-reported figures, labelled as someone else’s measurement, never mixed into the same sparkline. Boards dislike the split for one meeting, then prefer it, because the argument becomes shorter.

What to demote

Session counts inflate when a webview hiccups. Screen views inflate when a designer adds a step. “Engagement” as a blended index is how you hide the fact that you no longer know which human is which. Demote those to an appendix. Keep one money-adjacent behaviour and one quality caveat — refunds, chargebacks, clinical no-shows — so the star cannot be gamed by making the product worse.

What to stop pretending to know

You may not know the overlap between your iOS and Android people as tightly as you did. You may not know which campaign yesterday’s organic install “really” was. Write that down. A north star that admits a hole is still a star. A north star that fills the hole with modelled users is a different genre, and should live in a paper with methods, not on the first slide of a Tuesday exec.

Board Briefing Craft spends a day rewriting one slide under these constraints. It is not a DMA legal clinic. For that, call counsel. For the measurement sentence, start with a behaviour you can still see in your own event stream, then walk the Signal Atlas so you do not skip from a missing identifier to a redesigned home screen.