GA4 for your store: six events your data is worthless without

Most online stores have GA4 installed and collecting something. The problem is that what it collects does not let you make a single decision: you see sessions and "conversions," but not which products and categories actually make money.

Six events fix that.

Six events

Event	When it fires	Why it matters
view_item_list	viewing a category	which categories people actually look at
view_item	viewing a product page	which products get interest and which just sit there
add_to_cart	adding to cart	the first sign of intent to buy
begin_checkout	starting checkout	where you start losing people
add_shipping_info	choosing shipping	whether shipping cost is scaring people off
purchase	a successful order	revenue, products, channel

The key detail: every event needs to pass products with price and category, and purchase also needs an order ID and total. Without that you see event counts but not revenue by product — which is the whole point.

Why these six

Together they form a funnel that shows exactly where the money leaks:

category → product page → cart → checkout → shipping → payment

A drop between view_item and add_to_cart is a product-page problem: missing photos, missing specs, nothing to decide on. A drop between begin_checkout and purchase is a checkout problem: too many fields, too few payment methods, an unexpected shipping cost.

Without these stages split out, all you see is "1.2% conversion," with no way to know what to fix.

How to check it is actually working

The most common situation: events are "set up," and half of them either do not fire or fire with no data.

1. Open DebugView in GA4 and the Google Analytics Debugger extension.
2. Walk the whole buyer journey yourself: category → product → cart → checkout → payment.
3. Check that every event actually appears and carries a products array with price.
4. Place a small test order and confirm purchase arrives with the correct total.

Almost everyone skips the last step — and that is exactly where half the bugs live.

Three mistakes that show up the most

1. purchase fires twice

The event is set up both in the store’s theme and in GTM. Revenue in reports is double the real number. Easy to catch by reconciling against your CRM — so do it every month.

2. purchase fires on the "thank you" page

The customer refreshes the page — the event fires again. Tie it to the order ID and filter out repeats.

3. No category on products

Without item_category you cannot look at revenue by category — which is the exact report all of this exists for.

Three reports to check every week

1. Revenue by category. Shows what actually feeds the store. Very often the category with the most views is not the one that makes money.
2. Product-page-to-purchase funnel. One drop you can see here usually costs more than a month of ad spend.
3. Channels and sources by revenue. Not sessions — revenue. A low-traffic, high-ticket channel is often more important than your main one.

Merchant Center and the feed

If you are planning Google Shopping, check right away that prices match between the feed, the page, and the structured data. A mismatch is the most common reason products get rejected, and it usually surfaces only after you have already launched the ads.

The main point

Analytics gets set up before you start spending on traffic. Otherwise, six months in, you will have a feeling that "something is working" and no data to tell you what.

It is a few hours of work, once — and the only real basis for every decision after it.