A record label's move to a headless storefront, with the marketing site on one domain and checkout on another, broke attribution end to end. Ad platforms could not connect purchases to clicks, analytics showed three identity systems that never joined, funnel counts were inflated by duplicate events, and a rogue third-party pixel was silently corrupting the data layer. The brand was spending on ads with no reliable view of what any of it returned.
What we did
A forensic measurement rebuild. We identified and removed the rogue pixel, which had duplicated standard event names to mask itself. We established the one identifier that survived the cross-domain journey, the cart token, and used it as the deterministic join key: capture attribution data at checkout start, restore it at purchase. Then we deduplicated the double-firing funnel events, fixed conversion tags pointing at events the site never sent, and stitched analytics sessions back together across both domains.
What changed
The label can now see real acquisition cost per release and per channel. Ad budget decisions moved from faith to evidence, and the measurement layer survived the exact architecture that breaks tracking for most brands who attempt it.
The MQL target hit for the first time in over a year
Marketing and sales reconnected through one rebuilt measurement layer. The MQL target fell inside six months.