Retail Media Benchmarks 2026: Amazon, Walmart Connect & Instacart ROAS and CPC Compared

US retail media hits $69B in 2026. Amazon ACoS averages 32%, Walmart Connect CPCs run 55% lower than Google, and Instacart ROAS hits 6.7x for grocery brands. Here's what the benchmark data actually shows and how to use it.

Amazon Advertising Benchmarks 2026

ACoS (Advertising Cost of Sales): 32% average across categories. Competitive categories like supplements and electronics run 40–50%; defensive or niche categories can achieve 15–20% ACoS. Target ACoS should be set below your break-even ACoS, which depends on margin.

ROAS: Average 3.1x across Sponsored Products. Sponsored Brands run slightly lower at 2.6x but drive stronger branded search lift. Sponsored Display delivers 1.8–2.4x but is most valuable for retargeting and competitor conquesting.

CTR: Sponsored Products average 0.4–0.6% in most categories. Above 1% is excellent. Below 0.2% usually signals poor keyword/product match or low-quality imagery.

Walmart Connect Benchmarks 2026

Walmart Connect CPCs run approximately 55% lower than Google Shopping for equivalent product categories. This creates strong ROAS for brands already selling on Walmart.com. Average ROAS: 4.2x. The audience skews older and more value-oriented than Amazon's, which benefits CPG, home goods, and family products.

Instacart Ads Benchmarks 2026

Instacart delivers the highest ROAS of any retail media platform for grocery brands: 6.7x average across sponsored product placements. Conversion rates average 18–25% because users are already in an active purchase mindset. CPCs average $0.35–0.75 depending on category competitiveness.

Kroger Precision Marketing Benchmarks 2026

KPM offers first-party purchase data from 60M+ loyalty card members. Average ROAS: 4.8x for CPG advertisers. Strongest performance for mid-funnel campaigns targeting lapsed buyers and competitive switchers.

How to Prioritize Retail Media Investment

Start where your products are already selling. If you have distribution on Amazon and Walmart, test Sponsored Products on both before expanding to display or off-site formats. Measure incrementality — not just reported ROAS — using holdout testing after your first 90 days.