Glossary of Ad Metrics

AOV — Average Order Value. Total revenue divided by total orders. Agency AI pulls this from your Shopify order history.

Blended ROAS. Total store revenue divided by total ad spend across every channel. The honest version of ROAS, because it can't be double-counted between Meta and Google.

Break-even ROAS. The return on ad spend where you stop losing money. Calculated as 1 ÷ gross margin, so a 40% margin means a break-even ROAS of 2.5. You set this on the Brand page.

CAC — Customer Acquisition Cost. What it costs to acquire a genuinely new customer. Different from CPA, because CPA counts repeat buyers too. Agency AI separates them using your Shopify order history.

Conv — Conversions. The number of times someone completed your optimization event, usually a purchase. Attributed by the platform, so it won't match Shopify exactly.

CPA — Cost Per Acquisition. Ad spend divided by purchases. Your most important efficiency number after ROAS.

CPM — Cost Per Mille. What you pay for a thousand impressions. Rising CPM with flat CTR usually means audience saturation or increased auction competition.

CTR — Click-Through Rate. Clicks divided by impressions. A falling CTR on a previously strong ad is the clearest early signal of creative fatigue.

Engage-through. Meta's category, introduced March 2026, for conversions that follow a non-link interaction — a like, share, save, comment, or a video view of 5 seconds or more. Fixed 1-day window.

Frequency. Average number of times each person saw your ad. Above 2.5 on a prospecting audience, expect performance decay. Agency AI gates budget increases on this.

Learning phase. The period after launching or significantly editing an ad set while the platform's algorithm gathers data. Performance during it is volatile and should not be acted on.

MER — Marketing Efficiency Ratio. Total store revenue divided by total marketing spend. Same math as blended ROAS, framed as an efficiency ratio, and immune to the attribution arguments between platforms.

Optimization event. The action you've told the platform to optimize for, usually Purchase. Meta needs about 50 of these per ad set per week for stable delivery.

ROAS — Return On Ad Spend. Revenue attributed to an ad divided by what that ad cost. A ROAS of 4.0 means four dollars back per dollar spent, before you account for the cost of the product.

Spend. What you actually paid the platform over the reporting period.

tROAS — Google Target ROAS (different your Agency AI account Target ROAS). The return you tell Google's Smart Bidding to aim for. Agency AI adjusts this rather than your budget, because Google's bidding responds faster and more predictably to a target change.

Target ROAS (Agency AI). The profit goal your recommendations are measured against, always at or above your break-even ROAS. Not the same thing as Google's tROAS bidding setting, though Agency AI uses the former to inform the latter.