Marketing efficiency isn't ROAS. ROAS tells you one channel's return, not whether the whole machine is running well. Real efficiency is output, revenue or profit, per dollar spent and per hour your team spends managing it. Most Shopify brands lose track of both at once, which is why the push to improve marketing efficiency for a Shopify brand usually starts with a messy spreadsheet, not a strategy session.

Why Marketing Efficiency Breaks Down on Shopify