What are blended metrics?

Blended metrics combine data from multiple advertising platforms and your Shopify store into unified calculations. Instead of viewing Meta Ads and Google Ads performance separately, blended metrics give you a single, cross-channel view of your total marketing efficiency.

This is important because most Shopify merchants advertise on multiple platforms. Looking at each platform in isolation gives you an incomplete picture — and platforms tend to over-attribute conversions to themselves. Blended metrics use your actual Shopify data as the source of truth for revenue and customer acquisition.

Blended metrics reference

Metric	Formula	What it tells you
Blended Spend	Google Ads Cost + Meta Ads Spend	Your total investment in paid advertising across all connected platforms.
Blended Impressions	Google Ads Impressions + Meta Ads Impressions	Total number of times your ads were shown across all platforms.
Blended Clicks	Google Ads Clicks + Meta Ads Clicks	Total traffic driven by all your paid campaigns.
Blended CTR	(Blended Clicks / Blended Impressions) x 100	Overall ad engagement rate across platforms. Useful for tracking changes in ad effectiveness over time.
Blended CPC	Blended Spend / Blended Clicks	Average cost per click across all platforms. Helps you understand your overall traffic acquisition cost.
Blended CPM	(Blended Spend / Blended Impressions) x 1,000	Cost per thousand impressions across all platforms. Reflects overall audience reach efficiency.
Blended ROAS	Shopify Total Revenue / Blended Spend	The most important blended metric. Uses your actual Shopify revenue (not platform-reported conversions) divided by total ad spend. This gives you the true return on your advertising investment.
Blended CAC	Blended Spend / Shopify New Customer Count	Customer Acquisition Cost calculated using total ad spend and actual new customers from Shopify. Tells you how much it costs to acquire each new customer through paid channels.
Blended Conversions	Google Ads Conversions + Meta Ads Website Purchases	Total platform-reported conversions. Note: this uses platform attribution and may double-count some purchases.
MER (Marketing Efficiency Ratio)	Shopify Total Revenue / Blended Spend	Same calculation as Blended ROAS, sometimes referred to as MER in industry terminology. A MER of 5 means you earn $5 in revenue for every $1 spent on ads.

Why blended metrics matter

The attribution problem

Each ad platform has its own attribution model and claims credit for conversions based on its own rules:

Meta Ads attributes a purchase if someone clicked an ad within 7 days or viewed an ad within 1 day before purchasing.
Google Ads attributes conversions based on its own conversion tracking and attribution settings.
Both platforms can claim the same purchase, meaning platform-reported ROAS totals are inflated.

How blended metrics solve this

Blended ROAS and Blended CAC use your Shopify store as the source of truth:

Revenue comes from Shopify — actual orders, actual revenue. No attribution guessing.
New customers come from Shopify — first-time buyers based on complete order history.
Spend comes from the ad platforms — your actual investment.

This combination gives you the most honest picture of your marketing efficiency.

How to interpret blended metrics

Blended ROAS of 3x-5x is generally healthy for DTC e-commerce brands, but this varies by margin structure. If your gross margins are 70%, a 2x ROAS may be profitable. If margins are 30%, you may need 5x or higher.
Blended CAC should be lower than your LTV. Compare your Blended CAC to the customer lifetime value shown in Datadrew's Cohort Analysis dashboard. A healthy LTV-to-CAC ratio is typically 3:1 or better.
Blended CPC trends tell you about market competition. Rising CPC across both platforms usually means more advertisers are competing for your audience.
Platform ROAS vs. Blended ROAS gap: If the sum of Meta ROAS and Google ROAS is much higher than your Blended ROAS, there is significant attribution overlap. This is normal and expected.

Blended metrics vs. platform metrics: when to use each

Use case	Which metric to use
Evaluating overall marketing efficiency	Blended ROAS, Blended CAC
Deciding total marketing budget	Blended ROAS, MER
Optimizing a specific Meta campaign	Meta platform ROAS, Meta CPC
Optimizing Google Shopping bids	Google Ads ROAS, Google Cost per Conversion
Reporting to stakeholders	Blended ROAS (most accurate for business-level reporting)
Comparing channel efficiency	Platform-specific Cost per Conversion side by side