How to set up conversions (key events) in GA4 - Zephyra Studio

Goals in GA4, now called key events, are the actions you want repeated: a submitted form, a click on a phone number, a completed purchase. The process has three steps: the event has to exist first, then it gets marked as a key event in the admin area, and finally you check that it is counted as many times as the action occurred. The biggest mistake is not technical but a decision about what to mark, because when everything is marked as a key event, optimisation no longer knows what business is. That is why one to three actions that genuinely lead to revenue get marked, and everything else is measured as a supporting event.

What gets marked as a key event

A key event should be an action you would pay for. If someone submitted a form or called by phone, that is an event worth counting, because behind it stands a person ready to talk.

For a store it is a completed purchase, and for services a submitted form or a call. For businesses working locally, a click for directions or on the number in the Maps card can be as valuable as an enquiry, because a visit often follows.

What should not be mixed with key events are micro-actions: viewing the price list, opening a service page, scrolling halfway down. They are measured as supporting events, because they help explain the path to an enquiry without being a result on their own.

That is why there should be no more than three key events. When there are ten, the enquiry count gets lost among them, and if the same event also feeds advertising, the optimisation spreads across actions that bring no business.

How an event gets set up

Order matters, because only an event that already exists in analytics can be marked as key. The process comes down to a few steps, and most of the work is in verification rather than configuration.

• Check what is already measured automatically, because enhanced measurement covers outbound clicks, file downloads, site search, scrolling and video interaction
• For forms and calls, the event is sent either from the code or through the tag management tool, with a trigger on the specific action
• If the event does not exist, create it based on an existing event with a condition that isolates it
• In the admin area, in the events section, switch on the key event flag for that event
• Check in the debug view or the realtime report that the event fires exactly once per action
• If the conversion is also used in advertising, import or link the accounts, taking care that the same action is not measured twice

How to check that counting is correct

The first check is manual: submit the form from a phone, or from a computer outside the office, and see whether the event appeared. If it appeared twice, the trigger is set up in a way that also catches a page reload.

The second check is comparing with reality. If analytics shows twenty enquiries in a week while fifteen arrived by e-mail, something that is not an enquiry is being counted. A difference of five to ten per cent is usual, while a difference twice as large means an error.

The third check concerns consent. If scripts load before the visitor accepts cookies, part of the events will not be sent, so the enquiry count in analytics differs from the real one. On sites with strict settings that is expected and is taken into account when reading the data.

The fourth check is internal traffic. If visits from the office and test messages are not excluded, the key event count rises without business, and after a month nobody knows what the real result is.

Key events and advertising conversions are not the same

A key event in analytics counts every time it happens. A conversion in advertising can be configured to count once per click, and it uses a conversion window that defines how long after a click the action still belongs to that click.

It follows that figures in the two tools differ as a rule, and that is not an error. What is an error is measuring the same action both by an on-site tag and by the analytics import, because then one enquiry becomes two in the advertising report.

That is why one source is chosen for optimisation. If advertising uses conversions imported from analytics, then the on-site tag in Ads is not set up for the same action. The linking process is described in more detail in our article on linking GA4 and Google Ads.

What is worth measuring and what is not

The list of events should be short and should change a decision. If an event is not used in any decision, measuring it only costs time during setup and space in the report.

• Worth it: submitted form, click on a phone number, completed purchase, booking, started chat in a support window
• Worth it for local businesses: a directions request and a click on the number in the Maps card
• Worth it for B2B services: downloading a price list or brochure, because that is the first step before an enquiry
• Not worth it as a key event: page views, scrolling, every click, logging into the admin area
• Not worth it: tracking your own visits and test messages, because it raises the count without business
• Worth it as a supporting event, not a key one: viewing a price list, opening a service page, watching a video

Source

Key takeaways

• A key event should be an action you would pay for, not every action on the site.
• Keep key events to one or three, because optimisation scatters with many goals.
• The event has to exist first, and only then gets marked as a key event in the admin area.
• The key event count is compared with the real number of enquiries, which is where duplicates and gaps show up.
• Key events and advertising conversions are counted differently, so the same action is not measured twice.

Conclusion

Without marked conversions, analytics measures traffic rather than results, and every decision about content and advertising stays a guess. Setup takes an afternoon and verification a few days, which is where duplicates or missing events most often surface. If you are setting measurement up now, read our article on tracking conversions in Google Ads first, because the checks there apply to analytics too, and the wider picture is covered by our analytics and CRO service.