Why measure at all
You can run on intuition for a while — but intuition can't tell you where you're losing people. Measurement turns the dark middle of your funnel into steps you can see and fix.
In this chapter's workbook
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You can run a product on intuition for a while. The problem is that intuition can't tell you where you're losing people. You see the top number — signups, traffic — and the bottom number — revenue, active users — and everything between them is dark.
Measurement turns that dark middle into a sequence of steps you can see through. When 1,000 people land on your site, you want to know how many sign up, how many reach the moment the product becomes useful, and how many are still around next week. Each of those is a place you can lose people, and each is a place you can fix. You cannot fix a leak you cannot see.
This is the first move of the operating model from the opening chapter. A growth team doesn't argue about whether onboarding is confusing — it looks: 41% of new users drop between signup and first project, here are the replays. Measurement is what converts opinions into a shared, checkable picture of the funnel, and it's why the course starts here. Everything downstream — which journeys you build, where you spend on ads, what you tell the team in the Monday review — is only as good as the data underneath it.
That is the entire job of a product analytics tool: make the leaks visible so you can work on the right one. PostHog is the tool this course uses to do it. The next few pieces are what's actually in it, and later in this chapter comes the honest comparison with everything else you could pick instead.
The discipline that goes with the tool — what to measure and why — is the AARRR framework (Acquisition, Activation, Retention, Referral, Revenue), and it gets its own chapter. This chapter is about the instrument.
Check-in
Who's on the team that will act on these numbers?
Before you move on
This chapter's workbook items — sign in free and they save as you go:
1 — What PostHog is, and why you want it
The tool you'll measure with, why measuring is the first job of a growth team, how event-based analytics differs from GA4, what else is on the market, and what it really costs — in ten short pieces.
One pipeline, one identity
PostHog's structural advantage over stitching point tools together: one event pipeline and one model of who your users are, under everything. The nine-minute official demo, digested.