
MER
Total revenue divided by total marketing spend. A system-level number no channel can manipulate.
Net Acquisition MER
New-customer net sales divided by total ad spend. The honest number, because retention belongs to email and SMS.
NCAC
Ad spend divided by new customers from Shopify. Your true cost to win a brand-new customer, usually 2 to 4 times your reported CPA.
LTGP:CAC
Lifetime gross profit divided by acquisition cost. 3:1 is the floor to scale.

A live look at the Growth Dashboard.