Stripe knows exactly how much each customer paid. It doesn't know which ad brought them. BrainyMetrics joins the two: payments, subscription renewals (marked recurring), refunds, customer emails and phones, and Stripe customer ids are imported and matched to the person's journey.
Connect the webhook for real-time sales, a restricted read-only API key for complete data, or ideally both. With a key, Stripe is re-checked every 15 minutes for new charges and refunds, catching anything a webhook missed, and you can backfill up to 730 days. Webhook and API copies of a payment share an order id, so they merge into one order instead of double counting.