Revenue jumped 9.3% to $26.4 billion, but rising fees, ad costs, and discounts ate into margins. The brands that won tracked profit, not sales, in real time.
U.S. online shoppers spent more than $26.4 billion during Prime Day 2026, a 9.3% increase over last year, according to Adobe Analytics. That kind of growth suggests clear revenue wins for brands, but revenue alone doesn’t tell the whole story.
To capture those sales, brands took on higher costs across the board. Media spend increased as more brands competed for the same placements, discounts grew to win the sale, and higher fulfillment fees shrank profits. To determine whether Prime Day actually paid off, brands needed to watch their margins, not their revenue.
Why Brands That Hit Record Prime Day Sales Still Lost Profit
Record sales numbers and a profitable Prime Day are not the same. To reach record sales, brands had to pay higher fees, bid more for ad placement, and offer deeper discounts, each of which cut into profit, so even if a brand sold more units than ever before, it could still have earned less than in previous years.
The Cost to Sell Each Unit Increased
Before discounts were even determined, brands already had to pay more to fulfill each unit this Prime Day. Amazon raised FBA fees in January 2026 and added a fuel and logistics surcharge in April, while tariffs pushed up the price of many imported goods. Each increase made margins tighter, so brands entered Prime Day already earning less per sale than a year ago.
Brands Had to Bid More Aggressively to Remain Competitive
Once the event went live, brands had to pay more to compete for sales, as a more saturated retail media market pushed up the price on every placement and cut the return on their ad spend. Additionally, Alexa for Shopping’s monthly users have increased by more than 115% year over year, and engagement has gone up nearly 400%, meaning more customers skipped search altogether and decided what to buy based on AI-generated product shortlists. Ultimately, while brands are spending more to compete, their ads are reaching fewer shoppers.
Promotions on Everyday Items Cannibalized Margins
Brands offered deep discounts on everyday products, like household items, personal care, and pantry staples, but much of that markdown went to purchases shoppers would have made anyway. Shoppers used Prime Day to restock products they regularly buy, simply pulling forward an order they would’ve placed in the weeks after the event. While brands may have moved more units during Prime Day, many likely saw those sales as borrowed from future demand, diminishing the event’s overall impact.
Also Read: Too Much Data. Not Enough “Why.”
How Brands Managed Their Margins in Real Time to Keep Prime Day Profitable
The brands that stayed profitable didn’t wait for a post-event report to tell them where execution fell short. They watched each unit’s margin shift as the four days played out and took action while the numbers could still change.
Continuous Monitoring
Brands that came out ahead deployed AI agents to recalculate each unit’s true margin in real time, as its deal price, fees, and ad costs changed throughout the event. When a discount and rising fees dropped a unit below the point where it still earned, they stopped paying to advertise it right away. A brand that only tracks revenue would have kept funding that sale for days, mistaking volume for profit.
Real-time Adjustments
Brands didn’t just cut spending on products that were no longer earning; they redirected it. As some units lost revenue on every sale and others continued to turn a profit, brands shifted budget toward the ones that could still convert. The same budget then produced better results, without a single added dollar of ad spend.
Optimized Pricing
Brands set a margin floor, the lowest price at which a unit still turned a profit, for every product before Prime Day began. As competitors cut prices and ad costs rose, the agent kept every discount at or above that floor, so a markdown continued to attract shoppers without dropping the unit price below the profit threshold.
Agent Execution Across the Catalog
No team can manually track every unit’s margin across four days and thousands of SKUs. Internal teams or supporting agencies refreshing dashboards could review their numbers only a few times a day, which is far too slow to keep up with a marketplace that changes by the minute. Instead, the brands that kept pace used agentic retail to track margins across the entire catalog and adjusted bids and budgets as conditions shifted.
Also Read: AI Should Remove Friction, Not Human Connection
Brands Claiming Record Prime Day Sales Aren’t Telling the Full Story
The brands that came out ahead this Prime Day were the ones that protected their margins by keeping every unit sold profitable. Some even decided to sit out the event altogether, rather than discount at a loss. No matter the approach, the takeaway was the same: a record sales event and a profitable one weren’t necessarily synonymous.
Higher fees, rising ad costs, and deeper discounts all cut into margin at once this Prime Day, and the brands that only measured revenue didn’t see the profit they were losing until the event was over, while the brands that came out ahead tracked what every unit earned in real-time and adjusted before returns deteriorated.
