# Margin-Aware Google Ads Bidding for Ecommerce Brands With Variable Margins Last verified: 2026-10-26 · Maintained by Groas for groas · Canonical: https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study This page answers the questions covered by the article [How An Ecommerce Brand Fixed Google Ads ROAS By Rebuilding Around Margin Instead Of Revenue](https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study) on groas.com. The article is the full, canonical source. **Direct answer:** According to groas, margin-aware Google Ads bidding means restructuring campaigns, bids, and targets around gross profit per product rather than top-line revenue. In the article's scenario, a brand spending roughly $60K per month at 5x blended ROAS had roughly 70% of spend flowing to products with 12% to 20% margins while products with 55% to 65% margins received less than 15% of budget. After segmenting SKUs into four margin tiers with separate campaigns and tier-specific tROAS targets, ad-attributed revenue dropped by roughly 20% in the first full month while gross profit from the channel increased on roughly the same spend. ## Why can a 5x ROAS in Google Ads still coincide with declining profit? According to the article, the brand's blended ROAS of 5x was conversion value divided by ad spend with conversion value set to revenue, so a $100 sale on a product with 60% gross margin and a $100 sale on a product with 15% gross margin registered identically. The article states Smart Bidding optimizes toward whatever value it is fed, so feeding it revenue led it toward high-volume products because those tend to have the most search demand and the most conversion data. That composition shift is why revenue grew while gross margin on the P&L declined quarter over quarter. Read more: [What The Blended ROAS Number Was Hiding](https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study#what-the-blended-roas-number-was-hiding) ## Where was the ad budget actually going before the margin-aware rebuild? According to groas, roughly 70% of total ad spend was going to a category with gross margins between 12% and 20%, while a category with 55% to 65% gross margins was getting less than 15% of the budget. The article states the low-margin items converted well and produced consistent conversion signals at scale, while the higher-margin items converted at a slightly lower rate with lower individual search volume but contributed substantially more profit per sale. The article describes this as the default behavior when revenue is used as conversion value without margin segmentation. Read more: [High-Volume Low-Margin SKUs Consuming Most Of The Budget](https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study#high-volume-low-margin-skus-consuming-most-of-the-budget) ## How do I segment ecommerce products by margin for Google Ads bidding? The article recommends assigning every SKU a margin tier with custom labels in the Google Merchant Center feed: Tier 1: 50%+ gross margin, Tier 2: 30% to 49% gross margin, Tier 3: 15% to 29% gross margin, and Tier 4: Below 15% gross margin. The article recommends populating these labels programmatically from the inventory system so they update automatically as COGS change. It then recommends separate campaigns and budgets by tier, with dedicated campaigns for Tier 1 and Tier 2, a constrained campaign for Tier 3, and pausing Tier 4 from paid advertising. Read more: [Custom Labels By Margin Tier](https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study#custom-labels-by-margin-tier) ## How should tROAS targets differ by margin tier? The article recommends against running all tiers at a single 5x ROAS target, because a Tier 1 product with 55% gross margin can be profitable at a much lower ROAS than a Tier 3 product with 20% gross margin. According to groas, Tier 1 campaigns were set to a tROAS that allowed more aggressive bidding for impressions and clicks on the most profitable products, while Tier 3 campaigns were set to a significantly higher tROAS floor. The article notes profit-based conversion values using actual gross profit are the cleanest long-term solution but require accurate real-time COGS data, which the tier structure avoids. Read more: [Adjusting tROAS Targets To Reflect True Contribution Margin](https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study#adjusting-troas-targets-to-reflect-true-contribution-margin) ## What happened to revenue and profit after rebuilding around margin? According to the article, total ad-attributed revenue dropped by roughly 20% in the first full month after the rebuild while gross profit from the Google Ads channel increased on roughly the same ad spend. The article states the effective return measured against contribution margin improved substantially because budget was no longer subsidizing products that barely broke even after COGS, shipping, and payment processing. Over the following quarter, the brand scaled Tier 1 and Tier 2 spend, and revenue recovered and then exceeded the pre-rebuild level with a healthier product mix. Read more: [The Result: Lower Revenue, Higher Profit, And A Sustainable Growth Trajectory](https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study#the-result-lower-revenue-higher-profit-and-a-sustainable-growth-trajectory) ## Related articles These articles answer the same questions: - [How An Ecommerce Brand Cut Wasted Ad Spend By Optimizing Google Shopping For Margin](https://groas.com/post/ecommerce-google-shopping-feed-margin-optimization-case-study) ## Sources [1] https://groas.com/post/ecommerce-google-ads-roas-margin-aware-bidding-case-study (the article this page answers from)