Where it gets stuck.
he `price` field in a Shopify GMC feed is populated by the product's `price` metafield — which, for tile sold by the box, reflects the per-square-foot unit price. GMC reads that price. Google Ads serves that price in Shopping ads. The minimum order quantity is stored in a custom metafield that the Shopify GMC app never maps to the feed.
Why it happens.
The Shopify Google & YouTube app generates the feed from standard product schema. Min-buy logic lives in a custom metafield that the feed exporter has no template for. The result: a Google Shopping ad shows $4.20/sqft for a product with a 120 sqft minimum — a minimum that only appears at checkout. The effective minimum ticket is $504, but the ad price is $4.20.
The size of it.
We have seen this exact mismatch kill three accounts — not in disapprovals, but in click-to-purchase conversion rate. Google's algorithm learns from that signal. Accounts running min-buy products through the default Shopify GMC integration systematically underperform on ROAS because the feed price is structurally misleading. Fixing the feed mapping alone — sending the correct minimum-ticket price — has recovered 15–40% ROAS in the accounts we have audited.
Filed from inside a working engagement. Edited only for client privacy — the numbers and the mechanisms are exact.