Purchase Event Attribution

Upstack Data attributes each purchase to the ad clicks that led to it and fires first-click, last-click, and single-click conversion events for your destinations.

When a customer buys something, Upstack looks back at the paid ad clicks that led to the purchase and fires extra conversion events based on what it finds:

• First Paid Click (fpc_*) — the first paid ad click in the customer’s journey
• Last Paid Click (lpc_*) — the most recent paid ad click before the purchase
• First and Only Paid Click (fopc_*) — when the journey had just one paid ad click

Each event is named for where the click came from, and Upstack forwards it to that destination. The first and last click can come from different places, so one purchase can send First Paid Click to Meta and Last Paid Click to Google Ads.

When the whole journey had just one paid click, Upstack fires only the fopc_* event — not fpc_* or lpc_*. If you optimize on fpc_* alone, those purchases will not count.

Available events

Each purchase fires up to two of these events: First Paid Click and Last Paid Click, or First and Only Paid Click on its own. A new customer’s order, or the first order of a subscription, fires an extra set.

Each destination names these events its own way — match them exactly when you set up conversions.

Meta

Attribution model	Any purchase	New customer	Subscription initial
First Paid Click	fpcMetaPurchase	fpcMetaNcPurchase	fpcMetaSubscriptionInitialPurchase
Last Paid Click	lpcMetaPurchase	lpcMetaNcPurchase	lpcMetaSubscriptionInitialPurchase
First & Only Click	fopcMetaPurchase	fopcMetaNcPurchase	fopcMetaSubscriptionInitialPurchase

TikTok

Attribution model	Any purchase	New customer	Subscription initial
First Paid Click	FpcTiktokPurchase	FpcTiktokNcPurchase	FpcTiktokSubscriptionInitialPurchase
Last Paid Click	LpcTiktokPurchase	LpcTiktokNcPurchase	LpcTiktokSubscriptionInitialPurchase
First & Only Click	FopcTiktokPurchase	FopcTiktokNcPurchase	FopcTiktokSubscriptionInitialPurchase

Google Ads

These are the names shown in Upstack. You map each one to a conversion action you choose in Google Ads.

Attribution model	Any purchase	New customer	Subscription initial
First Paid Click	fpc_google_purchase	fpc_google_nc_purchase	fpc_google_si_purchase
Last Paid Click	lpc_google_purchase	lpc_google_nc_purchase	lpc_google_si_purchase
First & Only Click	fopc_google_purchase	fopc_google_nc_purchase	fopc_google_si_purchase

AppLovin

These events fire and are visible in Upstack, but they are not sent to AppLovin — see below.

Attribution model	Any purchase	New customer	Subscription initial
First Paid Click	fpc_applovin_purchase	fpc_applovin_nc_purchase	fpc_applovin_si_purchase
Last Paid Click	lpc_applovin_purchase	lpc_applovin_nc_purchase	lpc_applovin_si_purchase
First & Only Click	fopc_applovin_purchase	fopc_applovin_nc_purchase	fopc_applovin_si_purchase

What you need to set up:

• Meta — Upstack sends these automatically as custom events, but you must set each one up in Meta Events Manager before you can optimize on it. See How to approve Meta custom events.
• TikTok — Upstack sends these automatically as custom events.
• Google Ads — map each event to a conversion action on the destination. Until you map it, the event fires but nothing reaches Google. See Set up Google Ads server-side conversions.
• AppLovin — not forwarded. AppLovin has no Conversions API, so there is nowhere to send them. The events are still generated, so you can see them in Upstack.

Attribution window

The attribution window decides how far back Upstack searches for paid clicks before a purchase. You can change it in Pixel Settings under Purchase Event Attribution:

Option	What it considers
Lifetime (default)	The customer’s entire journey
7 / 14 / 28 / 30 / 60 / 90 days	Only clicks within that many days of the purchase

Lifetime gives the most complete picture. Pick a shorter window if your purchase cycle is quick and you only want recent clicks to count.

Using the events

• fpc_* events tell you which campaigns introduce customers to your brand. Map fpc_google_purchase as a conversion action in Google Ads to optimize for first-touch acquisitions.
• lpc_* events show which campaigns close the sale. Compare FPC and LPC attribution to see which campaigns start journeys and which ones close them.
• fopc_* events mark purchases where one ad click drove the whole journey.

Related

Set up UTM parameters

Tag your ad URLs so Upstack can attribute clicks to the right campaign.

Configure Google Ads

Set up the Google Ads destination that receives these events.

Global event mappings

Map an attributed event to a conversion action on each destination.

Verify events

Confirm events are firing from your storefront.