Unlock Your Data in GA4

Your storefront sends a large amount of detail with every event — manufacturer part number, price band, dropship status, lifecycle, shipping class, and more. Analytics receives all of it and shows none of it, until you register each field as a custom dimension.

This is a one-time setup and it’s the difference between collecting data and being able to use it.

ℹ️ Note: This is standard Analytics behavior, not a limitation of your store. GA4 ignores any parameter it hasn’t been told to keep. The data is already arriving — you’re switching on the reporting.

Why it works this way

GA4 has a fixed set of built-in dimensions. Anything beyond that is a custom parameter, which arrives with the event, is stored on the hit, and is invisible in every report until registered.

⚠️ Warning: Registration is not retroactive. Only data collected after you register a dimension is reportable. Do this early — waiting six months means six months you can’t analyze.

Item-scoped dimensions

These describe a product. Admin → Custom definitions → Custom dimensions → Create, with Scope: Item.

Parameter	Suggested name	Answers
item_mpn	Manufacturer Part Number	Which MPNs sell
item_price_bucket	Price Band	Which price range drives revenue
item_is_on_sale	On Sale	Do discounts actually lift sales
item_is_dropship	Dropship	Do dropshipped items convert differently
item_lifecycle_status	Lifecycle Status	Active vs discontinued performance
item_is_superseded	Superseded	Are shoppers landing on replaced parts
item_freight_required	Freight Required	Does freight suppress conversion
item_shipping_class	Shipping Class	Shipping profile vs sales
item_has_video	Has Video	Does video content sell
item_has_downloads	Has Documents	Do spec sheets sell
item_days_on_shelf	Days On Shelf	How long stock takes to move
item_sku	SKU	Your own identifier
item_part_number	Part Number	Catalog part number

💡 Tip: You have room for 27 item-scoped dimensions. Register the ones tied to a decision you’d actually make — start with price band, dropship, on-sale, and freight.

📸 Screenshot placeholder: GA4 Admin → Custom definitions, creating an item-scoped dimension.

Event-scoped dimensions

These describe the visit. Same screen, Scope: Event.

Parameter	Suggested name	Answers
page_type	Page Type	Which page types convert
user_logged_in	Logged In	Do accounts convert better
session_count	Session Count	How many visits before buying
first_touch_source	First Touch Source	What originally introduced them
first_touch_medium	First Touch Medium	The channel that introduced them
first_touch_campaign	First Touch Campaign	Which campaign started it
lead_type	Lead Type	Which lead kinds convert
form_name	Form Name	Which forms perform
search_term	Search Term	What shoppers look for
metric / rating	Web Vital / Rating	Page-speed detail

💡 Tip: first_touch_* is the valuable set. GA4’s built-in attribution is last-click by default — registering these lets you compare what introduced a customer against what closed them.

Doing it

1. Open Analytics → Admin (gear, bottom-left)
2. Custom definitions → Custom dimensions
3. Create custom dimension
4. Dimension name — what you’ll see in reports (“Price Band”)
5. Scope — Item or Event, per the tables above
6. Event parameter — the exact parameter name, spelled precisely (item_price_bucket)
7. Save, and repeat

⚠️ Warning: The parameter name must match exactly, including underscores. A typo produces a dimension that silently stays empty forever.

Using them

After 24–48 hours of collection, they appear as dimensions in Explore and in custom reports.

Worth building first:

• Revenue by price band — which tier actually carries the business
• Conversion rate by dropship status — whether dropship hurts
• Revenue by first-touch source — true channel value, not last-click
• Sessions before purchase — your real consideration cycle

📸 Screenshot placeholder: A GA4 Explore report using a custom item dimension.

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