Meta Ads vs Google Demand Gen for Ecommerce: Which Channel Drives Better ROI?

For years, marketers have struggled to accurately compare Google Demand Gen campaigns with paid social channels like Meta Ads (Facebook and Instagram Ads) due to fundamental differences in attribution models, conversion windows, and reporting methodologies. As a result, Demand Gen performance often appeared weaker or less efficient when evaluated alongside paid social, despite driving meaningful upper- and mid-funnel impact.

In April 2025, Google introduced Platform Comparable metrics, a major update designed to better align Demand Gen attribution with paid social advertising. These metrics provide a clearer, more balanced view of cross-platform performance, enabling marketers to make more accurate, data-driven comparisons between Google Demand Gen and Meta Ads.

In this article, we’ll explain what Platform Comparable metrics are, why they matter for ecommerce advertising, and how to use them to properly evaluate, optimize, and scale your Google Demand Gen campaigns with confidence.

Table of Contents:

1. Why Comparing Google Demand Gen to Meta Ads Has Been So Hard 
2. What is the Demand Gen campaign type in Google Ads? 
3. What Are Meta Ads (Facebook & Instagram Ads)?
4. What Are Platform Comparable Metrics and Why They Matter
5. How Platform Comparable Metrics are Calculated
6. How to View Platform Comparable Metrics in Google Ads
7. How to Use Platform Comparable Metrics
8. How to Ensure Data Accuracy in Demand Gen Reporting
9. Final Thoughts

Why Comparing Google Demand Gen to Meta Ads Has Been So Hard

Historically, Google Ads and Meta Ads have measured conversions differently. Google often excluded view-through conversions (VTCs), while most paid social campaigns counted them automatically. This difference sometimes made Demand Gen appear weaker and Meta Ads stronger, making budget decisions more difficult.

As a Google Ads company working with eCommerce brands, we’ve seen teams pause campaigns, reallocate budgets, or misinterpret results simply because these attribution differences weren’t clear. Platform Comparable metrics solve much of this issue, but it’s still important to understand where each channel works best.

What is the Demand Gen campaign type in Google Ads?

Google Demand Gen is a Google Ads campaign type designed to help eCommerce brands generate demand and drive future sales by reaching potential customers before they actively search to buy.

Unlike traditional search campaigns that rely on existing purchase intent, Demand Gen focuses on upper- and mid-funnel marketing, introducing your brand, products, and offers earlier in the customer journey. This allows eCommerce businesses to build awareness, consideration, and intent, increasing the likelihood of conversions later through search or remarketing campaigns.

Demand Gen campaigns display visually rich ads across Google’s most engaging surfaces, including:

• YouTube (in-feed and Shorts placements)
• Google Discover
• Gmail

By combining high-impact creative, advanced audience targeting, and Google’s AI-driven optimization, Demand Gen helps eCommerce brands influence buying decisions at scale – making it a powerful alternative to social platforms like Meta Ads for top-of-funnel growth.

What Are Meta Ads (Facebook & Instagram Ads)?

Meta Ads, also known as Facebook Ads and Instagram Ads, are a paid social advertising solution that helps eCommerce brands drive conversions, sales, and revenue by reaching users who are closer to making a purchase.

Unlike Google Demand Gen, which focuses on introducing products earlier in the buyer journey, Meta Ads are especially effective at mid- to lower-funnel marketing. These campaigns capture attention on social feeds where users are actively browsing, discovering products, and engaging with brands – making them highly responsive to compelling offers and creative content.

Meta Ads excel at retargeting and conversion-focused strategies. For example, an eCommerce brand can retarget recent website visitors, cart abandoners, or past customers with a limited-time promotion or discount, turning existing intent into immediate sales and supporting short-term revenue growth.

By leveraging advanced audience targeting, behavioral data, and high-impact creative formats, Meta Ads remain one of the most powerful channels for scaling direct-to-consumer (DTC) ecommerce sales.

What Are Platform Comparable Metrics and Why They Matter

While each channel has its strengths, comparing them directly has always been tricky due to different attribution models. That’s why it’s important for eCommerce teams to understand when and how to use each channel effectively:

• Demand Gen performs best with longer consideration cycles, higher-value products, or campaigns focused on discovery. Strong creative assets help introduce your brand or collections early in the buyer journey. 
• Meta Ads excel with shorter buying cycles, impulse purchases, low-AOV products, or aggressive retargeting campaigns, driving immediate conversions and capturing demand closer to the point of purchase.
  

But the bigger challenge has always been how results are measured. Historically, Google and Meta used different attribution models, which often made Demand Gen appear weaker in reports, even when it contributed significantly to conversions.

Platform Comparable metrics solve this problem by including view-through conversions in Google Ads reporting and applying a 7-day click, 1-day view attribution window, aligning measurement with Meta Ads. As a result, marketers can evaluate cross-platform performance on equal terms, see the true contribution of Demand Gen in the funnel, and make more confident decisions about budgets, scaling, and channel roles.

How Platform Comparable Metrics are Calculated

At a high level, Platform Comparable metrics expand standard Google Ads reporting by adding view-through conversions to existing conversion data:

• Conversions (Platform Comparable) = Conversions + View-through conversions 
• Conversion value (Platform Comparable) = Conversion value + View-through conversion value
  

This doesn’t change how campaigns are optimized or bids are calculated — it simply provides a more complete view of Demand Gen performance for cross-platform compariso.

How to Ensure Data Accuracy in Demand Gen Reporting

Before making strategic decisions, ensure your data is accurate and reliable. Demand Gen campaigns often involve delayed conversions and multi-touch attribution, meaning numbers can shift as the full customer journey is captured.

To keep reporting precise:

• Double-check your numbers – compare Google Ads data with platforms like Google Analytics 4 or Northbeam.
• Account for attribution delays – track performance beyond 7 days for a full view.
• Review Assisted Conversions – go to Goals → Measurement → Attribution → Assisted Conversions for the indirect impact of campaigns.
• Verify conversion settings – make sure Google Ads attribution windows align with Meta’s (7-day click, 1-day view).