ARPU

ARPU — average revenue per user — is total purchase revenue divided by your number of active users over a period. In GA4 it answers a simple question: on average, how much is each visitor worth? Unlike total revenue, it strips out the effect of traffic volume so you can see value per person.

Why it matters

Total revenue tells you how the business did. ARPU tells you how well your site turns visitors into money — regardless of how many visitors you had. That distinction is the whole game for a small site. If traffic doubles but ARPU halves, you haven't grown; you've just attracted cheaper visitors. ARPU is the metric that catches that, where the topline figure hides it.

A concrete example

Say a small online store had 5,000 active users and $10,000 in revenue last month — an ARPU of $2.00. This month, a viral post brings 10,000 users but revenue only reaches $11,000. ARPU has dropped to $1.10. Traffic doubled, revenue barely moved, and ARPU tells you why: the new visitors weren't buyers. The headline looked like growth; ARPU revealed it wasn't.

The common misreading

The mistake is reading a falling ARPU as a failure. It isn't always. A successful top-of-funnel campaign will naturally dilute ARPU in the short term, because it brings in browsers before they convert. Read ARPU next to transactions and average purchase revenue — the three together tell you whether the dip is a problem or a phase.