Prime Big Deal Days wrapped on October 7. Two days later, Triple Whale published benchmarks that give sellers a fresh read on ad performance before Black Friday budgets get locked in. Spend jumped, platform-reported purchases rose faster, and overall median ROAS moved up. But day two cooled off, and the category results weren’t all headed in the same direction.
One note on the headline question: “returns” here means advertising returns, measured in part by ROAS. Triple Whale’s report doesn’t tell us how many products were returned by shoppers.
The full Prime Big Deal Days 2026 benchmark report compares October 6–7 with September 29–October 5. Its sample covers roughly 1,900 brands and 2,100 Amazon ad accounts. These are platform-reported metrics, not a readout of confirmed profit.
Spend jumped, and platform-reported purchases rose faster
Across the two-day event, average daily Amazon ad spend rose 148.7% against the prior week. Platform-reported purchases per day increased 183.4%, outpacing the spend increase.
That’s an encouraging signal: measured purchases grew faster than ad spend across the report’s sample. It still doesn’t tell you if a campaign made money. Platform-attributed purchases aren’t the same as incremental sales, and revenue isn’t profit. Discounts, fees, and the margin on the products sold still have a say.
The timing matters, too. The event ran October 6–7, and the report came out October 8, while there’s still time to use its findings for Q4 planning. If you’re checking deadlines alongside performance, see Parker-Lambert’s Q4 calendar and Prime Big Deal Days inventory coverage.
ROAS and conversion improved, but check the whole margin picture
Triple Whale’s median ROAS rose from 2.94x in the prior week to 3.11x during the event, an increase of 5.7%. Median conversion rate climbed from 9.96% to 11.77%, up 18.2%. Those are useful improvements, particularly for sellers who were trying to turn more of their event traffic into orders.
Two other numbers add some needed context. Median average order value fell 5.1%, from $39.95 to $37.91, while median cost per click rose 5.9%, from $1.44 to $1.52. The report also puts median cost per acquisition down 7.5%, from $14.81 to $13.70.
Put simply, shoppers converted at a higher rate, but the typical order was smaller and each click cost a little more. That can still work well, but not automatically. Check your own discount depth, Amazon fees, ad costs, and contribution margin. A better ROAS number doesn’t get the final word on profitability. Your spreadsheet may be less exciting, but it’s useful company.
Day one did more of the work
In Triple Whale’s measured data, ad spend was about $9.13 million on October 6 and $8.27 million on October 7. Median ROAS dropped from 3.34x on day one to 2.90x on day two. Median cost per acquisition rose 14.6%, from $12.81 to $14.68.
That doesn’t mean day two was a bad day for every brand. It does mean the two days shouldn’t be treated as one interchangeable block when you review your own event. Compare each day’s spend and sales with your break-even point. Then ask whether day two earned its budget, or whether you were mostly buying traffic at a weaker return.
Use that answer when you plan Black Friday pacing. If performance dropped late in the event, consider what you might change by product, campaign, or day. Carrying the same budget curve forward just because it’s already in the calendar is a plan, technically. It may not be a very good one.
Category results varied widely
Some categories saw sharper improvements than the overall median. Sports and outdoors led the report’s efficiency gains, with ROAS up about 27% and cost per acquisition down 23% versus the prior week. Home and garden posted a 13% ROAS gain and a 13% CPA decline. Consumer electronics’ ROAS rose 16.3%, while CPA was nearly flat, down 0.3%.
Automotive moved the other way: it had the largest significant ROAS decline, down 9.5%. There were mixed results elsewhere, too. Food and beverage ROAS dipped 1.5%, while pets and animals was nearly flat at a 0.4% decline.
These are comparisons, not targets. Triple Whale says its industry tables include categories with at least 20 shops, so smaller categories aren’t represented. Your product mix, pricing, and margins can also make your own result look quite different from the category median. Treat the benchmark as a prompt to investigate, not a scorecard you need to copy.
What to review before setting Black Friday budgets
Start with your own numbers. Compare event spend, ROAS, conversion rate, average order value, and CPA with your pre-event baseline. Then check each against your break-even thresholds. Averages can tell you what moved across the sample; your own account tells you if the move helped your business.
- Split the event by day. Compare October 6 and October 7 spend, sales, ROAS, and CPA. See if the second day earned the same pacing.
- Check the size and value of orders. If AOV fell, look at whether deeper discounts or a shift toward lower-priced products changed your contribution margin.
- Adjust by product and campaign. Use the better-performing parts of your event data to guide Q4 budgets, rather than increasing every campaign by the same amount.
- Keep the benchmark in its lane. Platform-reported purchases and ROAS are useful signals, but they don’t confirm incremental profit or product return rates.
Triple Whale’s event-wide figures show that efficiency held up as spend rose, with stronger conversion and a modest ROAS gain. Day two’s weaker metrics and the category differences are the reminders to look past the average. Before you move money into Black Friday, check what happened in your account and what your margins can support.
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