In a product-led motion, the signup is not the conversion. It’s the beginning of the funnel that matters — and most tracking setups end exactly there.
A PLG measurement chain needs four linked stages. Signup, with source preserved into the CRM. Activation — the first-value moment, defined in product events, not vibes: created the first record, invited a teammate, completed the core action. Qualification — usage plus fit scored into a PQL definition sales actually agrees with. Revenue — upgrades and expansion tied back to the original source, so CAC payback is computable per channel.
The connective tissue is one identifier that travels the whole chain: the same user key in the product analytics tool, the CRM and the warehouse. Without it you have four disconnected reports; with it you can finally answer the only question paid marketing exists for: which euro produced a paying, activated customer?
If your funnel report today stops at “signups”, your ads are optimizing toward the cheapest signups — which are reliably the worst ones.