Why do ad platform conversions not match analytics conversions?

Their counting rules differ. An ad platform attributes the conversion to its own last interaction, holds it inside its own attribution window and sometimes counts view-through conversions, while a site-side tool only sees the action that happened on the site. The gap is expected and both figures are correct within their own frame.

Which actions should be declared as conversions?

The outcome the business spends money or time to produce, and whose movement would change a decision. If a rate moving up or down would start or stop nothing, that action is an engagement measure rather than a conversion.

Conversion

Beginner

Updated Jul 11, 2026 Shahin editorial 2 min read

PronunciationEN/kənˈvɜrʒən/

A conversion is a visitor reaching an outcome the business has defined in advance as valuable, such as a purchase, a signup or a form submission.

No behaviour is inherently a conversion; it is a declaration, and the team decides which event counts as an outcome. Two choices sit behind every conversion figure: which action is counted, and what it is divided by, because a session-based rate and a user-based rate give different numbers for the same action and should never be placed side by side. There is also a genuine collision of vocabulary: ad platforms attribute conversions to a click or an impression and count them inside their own attribution window, even when the user returned later by another path, so the conversion count in an ad panel almost never matches the count of the same action in a site analytics tool. The common misreading is treating all conversions as equal; a newsletter signup and a purchase are both conversions and are not worth the same.

FAQ

Sources:GA4 — Key events (conversions)