Stop reporting installs. Only three numbers matter for a subscription app.

Open any app marketing dashboard and the biggest number on it is installs. It is the number that goes in the investor update, the agency report and the Slack celebration. It is also the number that tells you the least. Here are the three we actually run our apps on, and why.

1. Cost per trial

Not cost per install. An install is someone who tapped Get, which costs them nothing and tells you nothing. A trial start is someone who got through onboarding, saw the price and said yes to at least trying. Cost per trial is the first number that reflects both the ad and the product. When it rises, either the traffic got worse or the onboarding did, and you can test which.

Get it by keyword and by country. The cheapest installs and the cheapest trials are often not in the same place, which is the whole point.

2. Trial-to-paid rate

Of the people who started a trial, how many paid when it ended? This is the number that measures whether the app keeps the promise the store page made. It is almost entirely a product number: the first session, the first result, the first week. Marketing can move it slightly with better-matched traffic, but if it is low, no ad will fix it.

It is also the number that decides what you can afford to pay for a trial. Work backwards from it, not from what the auction happens to charge.

3. First renewal

A paid conversion is not a customer yet. A first renewal is. Someone who pays a second time has decided, with their own money and a month of experience, that the app belongs in their life. This is the number that tells you whether you have a business or a very good launch.

It arrives late, which is why most dashboards ignore it. Build the patience in. A keyword that looks expensive at the trial stage and excellent at the renewal stage is the best keyword you own.

What this changes in practice

• Bids are set from cost per trial and trial-to-paid, by country, not from cost per install.
• Creative tests are judged on trial starts, not taps.
• Product changes are judged on trial-to-paid and renewal, not on session length.
• The weekly report has three charts, and installs are a footnote.

How to get the numbers

Connect your ad platforms to an attribution tool that receives subscription events, so trial, paid and renewal are visible by campaign and keyword. Make sure the events are sent server-side from your subscription backend rather than from the app, or you will undercount. Then give the dashboard a week to fill in and stop looking at installs.

This is the first thing we set up when we take on an account, because every decision after it depends on it. More on how we work.