Your Google Ads drive traffic to your site, but customers buy on Amazon for Prime. You pay for the click, Amazon gets the sale and customer data.
Example: 40% of site visitors from Google Ads purchase same product on Amazon within 48 hours
Different prices across channels confuse customers and Google. Your $50 product on site competes against your $45 Amazon listing in Shopping results.
Example: Customers click expensive site ad, find cheaper Amazon listing, buy there
Products sell out on one channel but ads keep running. Overselling creates fulfillment nightmares and customer service costs.
Example: Shopping ads running for products sold out on site but available on Amazon
A customer sees your Google Ad, researches on Amazon, buys from eBay. Who gets credit? Most sellers can't answer this, leading to wrong optimization decisions.
Example: Cutting Google Ads causes Amazon sales to drop 30%
Different channels have different feed requirements. Managing multiple feeds leads to errors, inconsistencies, and disapprovals.
Example: Product updates on site not syncing to Google feed for 2 weeks
With a single asset group, Google optimizes for aggregate ROAS by heavily favoring your top 5-10 products. The rest of your catalog gets almost no impressions. Worse, low-margin products drag down profitability while appearing successful in aggregate.
Fix: Segment products by performance tier: Winners (scale), Potentials (test), Underperformers (cut or fix). Create separate asset groups for each.
PMax claims credit for brand searches that would've cost $0.30 through a dedicated brand campaign. Without exclusions, you're paying 3-5x more for customers already looking for you.
Fix: Add brand exclusions to PMax and run a separate Brand Search campaign with exact match keywords.
Missing GTINs, generic titles, no custom labels, and missing sale prices hurt your Shopping ad performance. Price inconsistency across channels
Fix: Create site-exclusive products or bundles not on marketplaces
Your 5x ROAS might look great until you realize 70% of sales are repeat customers who would've bought anyway. You're paying to acquire customers you already have.
Fix: Segment reporting by new vs returning customers. Set up customer match lists and analyze true CAC.
Not all campaign types work for multi-channel sellers stores. Here's what to skip:
Competes with your own marketplace listings
Traffic often converts on marketplaces
Attribution chaos with multi-channel
Follow these best practices to maximize your Multi-Channel Sellers Google Ads performance:
Budget: 25-35% • Target ROAS: 4-8x
Budget: 30-40% • Target ROAS: 3-5x
Budget: 20-25% • Target ROAS: 5-10x
Budget: 15-20% • Target ROAS: 2-3.5x