Ecommerce Event Tracking: What Should You Measure?
Which ecommerce events to track: product lists and views, search, filters, cart, checkout, purchase, refunds, wishlists, accounts and subscriptions.
Quick answer
Track the shopper actions that answer your business questions, with consistent names and parameters. Core ecommerce events cover product lists and selections, product views, search, add and remove from cart, cart views, checkout start and key steps, purchase and refund; add filters and sorting, variant and size guide interactions, wishlists, account events and subscription events where relevant. Use a widely recognized naming scheme such as GA4's recommended events, include currency, value and item details, deduplicate purchases by transaction ID, respect consent and test before release.
Concepts Before Tools
Event tracking is a concept, not a product. Whatever tool you use, each event is a named action with parameters: what happened, to which items, at what value, in which context. The event map above groups events by journey stage, using GA4-style names where Google defines them and descriptive custom names elsewhere. Start with questions (where do shoppers drop off, which products are viewed but not bought) and track what answers them. See ecommerce analytics and analytics architecture.
Core Ecommerce Events
Google Analytics 4 documents a set of recommended ecommerce events that many teams use as a naming standard even outside GA4 (Google Analytics documentation):
| Event | When it fires | Answers |
|---|---|---|
| view_item_list | A product list is shown (category, search, recommendations) | Which lists shoppers see |
| select_item | A product is clicked from a list | List effectiveness, positions |
| view_item | Product page viewed | Product interest |
| add_to_wishlist | Product saved | Future intent |
| add_to_cart / remove_from_cart | Cart changes | Product and cart behaviour |
| view_cart | Cart viewed | Cart engagement |
| begin_checkout | Checkout started | Checkout entry |
| add_shipping_info / add_payment_info | Checkout steps completed | Checkout drop-off |
| purchase | Order completed | Revenue, conversion |
| refund | Refund issued | Net revenue, returns |
| view_promotion / select_promotion | Promotions shown and clicked | Merchandising performance |
Parameters That Make Events Useful
Events without parameters can't answer product or merchandising questions. Include currency and value, and an items array with item ID, name, brand, category levels, variant, price, quantity and, for lists, list name and position. Purchases and refunds need a transaction ID. GA4's documentation, for example, supports up to 200 items per event and category levels item_category to item_category5.
{
"event": "add_to_cart",
"currency": "GBP",
"value": 89.00,
"items": [{
"item_id": "SKU-12345",
"item_name": "Trail Running Shoe",
"item_brand": "Brand",
"item_category": "Footwear",
"item_category2": "Running",
"item_variant": "UK 9 / Blue",
"item_list_name": "Search results",
"index": 3,
"price": 89.00,
"quantity": 1
}]
}Discovery Events Worth Adding
Standard events miss important discovery behaviour. Add custom events for search (with the query and result count), zero results, filter applied and removed (with attribute and value), sort changed and comparison added. These show how shoppers narrow the catalog and where discovery fails. GA4 also defines a search event with a search_term parameter. See site search and filters.
| Custom event | Key parameters |
|---|---|
| search | search_term, results_count |
| filter_applied | attribute, value, list_name |
| sort_changed | sort_option, list_name |
| compare_added | item_id, comparison_size |
| size_guide_opened | item_id, category |
Account, Wishlist and Subscription Events
Retention analysis needs events beyond the first purchase: sign_up and login (GA4 recommended events), wishlist additions, subscription created, skipped, paused, cancelled and renewed, and reorder actions. For subscriptions, server-side events from the subscription system are more reliable than browser events. See subscription retention.
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Platform Implementations
Platforms provide event foundations. Shopify's customer events include page_viewed, product_viewed, collection_viewed, search_submitted, product_added_to_cart, product_removed_from_cart, cart_viewed, checkout_started, checkout_contact_info_submitted, checkout_address_info_submitted, checkout_shipping_info_submitted, payment_info_submitted and checkout_completed, available to apps and custom pixels (Shopify developer docs). Map these to your analytics tool's names in your tracking plan and add custom events for discovery behaviour. See Shopify analytics.
The Tracking Plan
- Event name and trigger condition
- Parameters, types and example values
- Where it's implemented (theme, app, server)
- Destinations (analytics, ads, warehouse)
- Consent category
- Owner and last verified date
Data Quality
Deduplicate purchases by transaction ID, prefer platform-confirmed or server-side purchase and refund events, validate parameters (currency codes, item IDs matching your catalog), and compare daily purchases with platform orders. Consent choices and blockers mean analytics won't match orders exactly; monitor the gap for sudden changes. See analytics architecture.
Worked Example
An illustrative scenario: a store tracks only page views and purchases and can't tell why category pages underperform. The team writes a tracking plan with list, item, cart and checkout events, custom search, filter and sort events with parameters, and refund events from the server. After release and validation, it finds that one category's filters are rarely used and that a checkout step has a disproportionate drop-off. See funnel analytics.
Event Naming Conventions
Pick one convention and stick to it: lowercase with underscores (add_to_cart), verb-object order, consistent parameter names and units. Prefer recognized names (such as GA4's recommended events) where they exist, and document custom events in the tracking plan. Renaming events later breaks historical comparisons, so decide early.
Common Mistakes
- Tracking without questions
- Events without item parameters
- Duplicate purchase events
- No refund events
- Inconsistent names across platforms
- No testing before releases
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Conclusion
Good event tracking captures the actions that answer your questions, with consistent names, useful parameters and verified quality. Start with core ecommerce events, add discovery and retention events and keep a living tracking plan. For turning events into product insight, see ecommerce product analytics.
Common questions
Recording specific shopper actions (viewing products, searching, filtering, adding to cart, checking out, purchasing, refunding) as structured events with parameters, so you can analyse behaviour, funnels, products and experiments.