Signal loss, reported ROAS, and what to do

After ATT, platform-reported ROAS is a directional metric, not accounting truth. Founders who budget from Ads Manager alone over- or under-spend versus Shopify or Stripe reality.

Triangulate truth

Compare Meta purchases + CAPI events to backend revenue by cohort week. Use MER (total revenue / total ad spend) weekly as the boss metric; use ad-set ROAS for creative decisions only.

Compensate with creative

When targeting is opaque, creative is the lever you control. Broader Advantage+ with strong assets beats micro-audience hacking. Document winning hooks in TIMA memory so the next campaign starts informed.