CommerceIQ says ecommerce efficiency is improving before Prime Day

CommerceIQ says brands are entering Prime Day and the second half of 2026 with better advertising efficiency, higher conversion rates and stronger inventory than earlier this year. But the company’s data also shows stockout-related revenue loss is rising, especially for high-performing products. Why it matters: - Brands are heading into Prime Day with stronger ecommerce fundamentals, which could lift sales if inventory and media execution hold. - The biggest risk is not a broad shortage of stock, but lost revenue from out-of-stock gaps on higher-revenue products. - CommerceIQ’s findings suggest AI-assisted shopping may be changing how consumers buy, making in-stock availability more important at the moment of decision. What happened: - CommerceIQ released year-to-date performance data on June 18, 2026, based on aggregated and anonymized platform data from brands selling on Amazon. - The data shows advertising efficiency improved through May 2026, conversion rates rose, and inventory levels strengthened heading into Prime Day and the second half of the year. - Guru Hariharan, CommerceIQ founder and CEO, said conversion rates are up 15% year to date and inventory positions are healthier than earlier this year. The details: - Retail media spend increased about 10% year over year. - Return on ad spend climbed to about $5.80, the strongest level in nearly two years. - The average conversion rate reached 29.8% in the first five months of 2026, up from 26% in the same period last year. - April conversion hit 31%, the highest monthly point of the year. - Glance views stayed relatively flat over the same period. - On-hand inventory increased about 12% year over year. - Revenue lost to stockouts rose about 24% year over year. - Out-of-stock rates stayed relatively stable, which suggests the revenue loss is being driven by stockouts in high-performing products. - Hariharan said Amazon reported Alexa for Shopping users are 60% more likely to convert than other shoppers. - Hariharan said that when AI guides shopping, missing stock can mean losing both a sale and a customer relationship. Between the lines: - The data points to a healthier ecommerce environment than earlier in 2026, but execution risk is shifting from broad performance to product-level availability. - Flat glance views alongside rising conversions suggests more shoppers may be arriving with stronger purchase intent, which is consistent with AI-assisted shopping behavior. - The revenue impact of stockouts may be getting worse even without a large change in overall out-of-stock rates because the missing products are more valuable. - Hariharan framed agentic retail tools like AllyAI as a way to help brands keep pace operationally during peak shopping periods. What’s next: - Brands will use Prime Day and the broader summer shopping season to test whether stronger conversion and media efficiency translate into actual sales growth. - Inventory management will likely remain the main operational focus as demand spikes. - CommerceIQ says the report is available for download through its platform materials and website. The bottom line: - Ecommerce performance is improving, but stockouts on top-selling items could erase gains fast if brands do not keep products available when shoppers are ready to buy. More information