Should a Google Ads agency guarantee a specific ROAS?

A ROAS number is produced by things no agency controls: your product margins, your offer strength, your prices against competitors, seasonality, and what the auction does that month. An agency controls the process around those things, never the number itself. So a guaranteed number is a promise made about someone else's variables.

That leaves two options for the agency making it. Either they know it is not guaranteeable and are saying it anyway to win the deal, or they have written the guarantee so it can never actually pay out. Neither is a company you want inside your account.

Read the fine print on any results guarantee and you will usually find one of three escapes. The target only counts under conditions the agency defines, like a minimum spend or excluded months. Or the guarantee refunds a fee that was priced high enough to absorb the refunds. Or the measurement itself is soft: last-click ROAS flattered by brand search and retargeting, where the agency takes credit for buyers who already knew your name.

That last one is the quiet trick. A guaranteed number invites the agency to optimize toward whatever makes the number, not whatever makes you money. Broken incentives beat good intentions every time.

Demand a process you can inspect and an exit you can use. Concretely: tracking verified against your real Shopify orders so nobody grades their own homework, a clear reason and next step whenever results dip, weekly reporting, and no lock-in, so the agency has to re-earn the account every month. Month to month is the honest version of a guarantee: if it stops working, you leave.

Our answer to the guarantee question has always been the same word: no. What we do guarantee is a process built on data from 200+ stores, and we tell you straight when something is not working. There is also a full guide on our blog to verifying any agency's claims before you sign.