Up Against Two Giants, a Breast Milk Cooler Brand Grew Prime Big Deal Days Sales 48% on Under 4% TACoS

Prime Big Deal Days, October 6 to 7, 2026, vs. the same event in 2025

Two of the biggest names in baby gear sell the same kind of product. This small brand couldn’t outspend them, so it closed the price gap instead. Over Amazon’s Prime Big Deal Days, October 6 and 7, 2026, its portable breast milk coolers grew sales 48% and orders 67% on the same event a year earlier, with advertising at under 4% of sales. Day two finished 75% ahead of its 2025 match.

David, meet two Goliaths

The partner sells portable coolers that keep breast milk cold for hours away from a fridge, a product parents compare closely before they buy. Two much larger baby brands sell competing coolers on Amazon, and during an event their deal prices set the bar shoppers judge everything else against.

The brand’s ad budget was small, planned at $1K a day for the event. Most of its sales already came without ads, so the event had to win on price and conversion more than on ad volume.

The play: win the side-by-side

1. Close the price gap. At the partner’s request, the deal price on its main cooler dropped to $36, to compete more directly with the two larger rivals. A shopper comparing the three had less of a price reason to pick the bigger names.
2. Keep ads lean and let price work. Spend stayed near the planned $1K a day, running slightly over on day one when traffic was strong.
3. Line up the week after. Once the event ended, ad spend moved to a $300 daily cap on non-branded searches, and a 20% Brand-Tailored Promotion went to shoppers who had left the cooler in their cart, backed by Sponsored Display remarketing.

The scoreboard

Day one finished 25% ahead of the same day in 2025. Day two finished 75% ahead. Across both days, sales rose 48% and orders rose 67%, with TACoS under 4%. Three versions of the cooler showed the strongest growth.

Source: Amazon Seller Central, Prime Big Deal Days 2026 vs. 2025. Shown as an index to protect the partner’s data. Figures rounded down.

Across the event week, the conversion rate doubled on the week before, from 10.3% to 20.9%, and ACoS fell from 18.2% to 12.2%. More of the shoppers who reached the page bought, and each ad dollar went further.

Source: Amazon Seller Central and Amazon Ads. Sales and orders against Prime Big Deal Days 2025; conversion and ACoS for the event week against the week before. Figures rounded, each in the less flattering direction.

Why orders outran sales

Orders rose 67% while sales rose 48%, so the average order was worth 11% less than a year earlier. That was the price change at work. The brand gave up a few dollars per cooler to close the gap with the brands shoppers knew best, and in return it won many more orders.

With most sales coming from outside ads, the price did the heavy lifting the ad budget could not. Conversion doubling during the event week is the clearest sign: far more of the shoppers who reached the page chose this brand.

You can’t outspend the giants. You can make the choice easy. Close the price gap and let the product do the rest.

The full picture

All figures rounded, each in the less flattering direction. Year-over-year results are shown as percentages to protect the partner’s data.

Steal this if you compete with bigger brands

Three checks before your next event.

First, write down the event prices of the two or three products shoppers compare you against. If yours is clearly higher, more ad spend will mostly pay for clicks that end in someone else’s cart. Second, track orders and sales separately. If orders grow faster than sales, your price is winning comparisons; then check that the margin still works. Third, plan the week after the event before it starts. Cart abandoners and recent visitors are the cheapest shoppers to bring back.

A small brand cannot outspend the big ones during an event. It can still be the better buy on the page.

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