If I set up a data source like Redshift, do I need to already have revenue and purchase data tracked in that database? Also, how do you match users in the experiments with their purchases?

Hi Luan, You don't need to have data already, though you'll need some data to show results. We join from the exposure info, then to the metric info

@fresh-football-47124 Can you provide an example of a tracking callback script for BigQuery (without using GA4)? I’m unsure how to match anonymous "user IDs" with purchases. Do I need to send the "user ID" (for non-logged-in users) in the tracking callback script? Thank you Graham!

Hi! You don't likely want to send data to BigQuery without GA4. Instead, you can set up purchase tracking (and other e-commerce events) via GA4, which will allow you to match purchases between your experiment and other data. https://developers.google.com/analytics/devguides/collection/ga4/set-up-ecommerce