Prime Day 2026 Preview: 7 Shifts From 2025 to Guide Your 2026 Playbook

Prime Day 2025 broke records that advertisers will spend the rest of the year trying to replicate. CPC dropped to its lowest level in three years. CTR climbed to a three-year high. Brands ran a four-day event with the discipline of a two-day one. And in a year shaped by economic caution, pantry essentials drove more category growth than premium splurges did.

Each shift carries a signal about what’s coming in 2026. Read together, they describe a very specific event ahead: one where efficiency is the floor, AI handles the volume, and human judgment determines the strategy AI executes.

To prepare, we pulled the year-over-year shifts from Skai’s same-store-growth cohort of Amazon and Amazon DSP advertisers active during the July 2023, July 2024, and July 8 to 11, 2025 Prime Day events. Because 2025 was Amazon’s first four-day Prime Day, we split it into halves for a like-for-like comparison: Days 1 and 2 (the “first half”) and Days 3 and 4 (the “second half”), each compared against the equivalent day from 2024.

Efficiency hit a new floor

Two performance shifts stood out in 2025, occurring at the same time.

CPC dropped to $1.80 in 2025, down 10.4% from 2024’s $2.01, the lowest level in three years. CTR rose to 0.32%, up 33.3% from 2024’s 0.24%, the highest in the same period. Cheaper clicks and stronger engagement, happening together, at the most competitive auction window of the retail calendar. That combination is rare.

Year	CPC	% Change YoY	CTR	% Change YoY
2023	$1.95	Baseline	0.28%	Baseline
2024	$2.01	+3.1%	0.24%	–14.3%
2025	$1.80	–10.4%	0.32%	+33.3%

When it happens, several things have gone right at once: tighter audience targeting, sharper product listings, and bidding systems that adjust faster than humans can. By 2025, AI-driven bidding had matured enough that marketers could lean on it for in-flight optimization, which freed teams to focus on the inputs (creative, product data, audience definition) where they still have an edge.

According to Momentum Commerce, 25.6% of products on Amazon US featured discounts during Prime Day 2025, up from 23.6% in 2024. The average depth of those discounts decreased to 21.7% from 24.4%. Brands grabbed attention while protecting margin, which is part of why CTR climbed even as CPC fell.

What this means for 2026. The efficiency bar brands cleared in 2025 is now the floor. ROAS targets that looked ambitious last year are the baseline. Assume your competitors have closed the gap on AI bidding, and reallocate budget toward stronger creative and cleaner product data, because that’s where the next efficiency gains live.

Too much front-loading could be a defensible mistake

Going into 2025, the open question was whether a four-day event would double advertiser investment or whether brands would spread spend more strategically. The answer turned out to be unambiguous.

Metric	1st Half YoY Lift (Day 1 2024 vs Days 1 and 2 2025)	2nd Half YoY Lift (Day 2 2024 vs Days 3 and 4 2025)
Spend	+19.6%	+0.3%
Clicks	+26.1%	+19.7%
CTR	+33.6%	+34.4%
CPC	–5.2%	–16.2%

First-half 2025 spend was up 19.6% versus first-half 2024, with clicks rising 26.1% and CTR climbing from 0.24% to 0.32%. The second half tells a more interesting story. Spending held nearly flat year-over-year (+0.3%) while clicks still increased 19.7%, because CPC dropped 16.2% versus Day 2 of 2024. Advertisers adjusted bids to pace mid-event budget rather than push too hard early or late.

That reads like portfolio thinking, not panic buying. Methodological best practices for event splits like this one are outlined in the IAB Europe Retail Media Measurement Standards, which enable apples-to-apples intra-event comparisons.

If Amazon extends events again, and Walmart’s Deals Days have followed similar expansion patterns, the question stops being “how much do we spend on day one?” and becomes “how do we pace across a 96-hour window without burning out budgets by hour 48?”

What this means for 2026. Pacing is the strategy. AI dayparting and automated pacing tools earn their keep here, because no human can manually adjust bids fast enough across four days. The human’s job is to set the phase strategy and the guardrails. The AI’s job is to execute inside both.

Your tooling has to handle 3X volume, full stop

Year-over-year comparisons offer perspective, but they don’t capture the absolute scale of an event window. To show that, we compared the daily average across the four-day event to the daily average across the 30 days leading up to it.

Metric	Daily Lift vs 30 Days Leading Up
Spend	+198%
Clicks	+108%
Impressions	+114%
Conversions	+153%
Revenue	+197%

The numbers are stark. Brands spent nearly 3X more per day during Prime Day 2025 than they did in the weeks before. Clicks (+108% daily) and impressions (+114% daily) climbed smoothly rather than spiking, and daily revenue came in almost 3X higher than baseline. Operations scaled with the spend.

According to eMarketer, consumers also traded up in big-ticket categories like electronics (+57% sales growth) while still stocking up on essentials. Two-thirds of items sold on Amazon during Prime Day went for under $20.

The operational implication is the part that matters most. At 3X normal volume, a manual spreadsheet check is too slow. Anomaly detection, pacing monitors, and automated alerts move from “nice to have” to “non-negotiable” when one wrong bid file can burn a quarter’s budget in hours.

What this means for 2026. Plan for the 3X surge inside your tech stack first, your spend plan second. The brands who win the operational fight have time and headspace left over for the judgment calls that win the strategic one.

Event shoppers convert harder, so why are you tightening targeting?

This finding gets buried under the headline numbers, but it deserves its own section.

Clicks during Prime Day 2025 were up 108% versus the 30-day baseline. Conversions were up 153%. A 45-point gap between click volume and conversion volume tells you something specific: the shoppers Prime Day brings to your detail page convert at a higher rate than your normal traffic. The intent runs hotter. The wallets are open.

Most marketers respond to peak windows by narrowing targeting to protect efficiency. The data argues for the opposite. When the event itself is doing the qualifying, audiences you’d normally consider too broad become viable. Tightening cuts you off from the conversion lift you’d otherwise capture.

What this means for 2026. Broaden targeting during peak windows. This is one of the clearest cases where human judgment needs to override an AI optimization that defaults to narrow. The AI is solving for an in-period efficiency metric. The human is solving for incremental conversions at acceptable cost. Those are two different objectives.

DSP stopped being an enterprise-only format

Look at the format share of Amazon Ads spend over the past three Prime Days, and one trend dominates everything else.

Format	2023	2024	2025
Amazon DSP	8.7%	13.6%	15.6%
Sponsored Brands	17.4%	14.5%	10.9%
Sponsored Display	3.3%	2.6%	1.3%
Sponsored Products	71.6%	69.2%	72.0%

Amazon DSP’s share of total spend climbed from 8.7% in 2023 to 13.6% in 2024 to 15.6% in 2025. Indexed, DSP spend in 2025 is 2.73X what it was in 2023.

Skai’s VP of Commerce Media Kevin Weiss framed why: “Amazon DSP isn’t just for the biggest advertisers anymore. Amazon has been actively democratizing DSP access, making it easier for any brand, no matter the size, to fold DSP into their mix. That’s changing the way retail media strategies look across the board.”

That democratization shows up in the data. Across Prime Day 2025, smaller and mid-size brands leaned into DSP to reach audiences both onsite and offsite, for awareness and mid-funnel consideration, not just retargeting. The shift extends beyond Prime Day. Skai’s 2026 State of Retail Media research found that 52% of advertisers are reallocating display dollars from open-web DSPs to retail media DSPs, driven by closed-loop attribution (57%) that traditional programmatic can’t deliver.

What this means for 2026. Audit your DSP allocation before Q3. Brands not yet in DSP are two cycles behind. Brands already in DSP face a sharper question about portfolio shape across DSP and Sponsored Products, and that’s a human judgment call.

The middle of the format mix is hollowing out

The DSP story is half the picture. The other half is where those dollars are coming from.

Sponsored Display lost ground rapidly. Its share of total Prime Day spend was cut nearly in half year-over-year, from 2.6% in 2024 to 1.3% in 2025. Sponsored Brands has lost a third of its share over the same three-year window, dropping from 17.4% in 2023 to 10.9% in 2025. Sponsored Products has held steady around 70 to 72%.

This isn’t because those formats stopped working. DSP now covers the off-Amazon reach use case that Sponsored Display historically filled. Brands are concentrating mid-funnel spend in formats that scale better. The format mix is consolidating toward two ends: Sponsored Products at the conversion floor and DSP at the reach ceiling.

What this means for 2026. Re-justify every dollar of Sponsored Brands and Sponsored Display spend before Prime Day ’26. They still earn a place for specific use cases like brand launches, defensive headline coverage on branded queries, and retargeting for new product launches. The default allocation logic, though, needs revisiting. Auto-budget tools that optimize for short-term efficiency will quietly drift you back into a 2023 mix without you noticing.

Prime Day quietly became a subscription acquisition event

The category data tells the most interesting story about consumer mood.

For Prime Day 2025, Food & Grocery ad spend grew more than 2.2X compared to 2023. Health saw nearly 2X growth in the same period. Those weren’t anomalies. According to eMarketer, two-thirds of Prime Day 2025 items sold for under $20, with products like protein shakes and cleaning supplies among the top sellers. Skai’s Summer Deals Consumer Survey caught early signs of the shift in May 2025: 46% of consumers expressed interest in deals on groceries and household essentials, outpacing the year-over-year increase for electronics, fashion, and beauty (tied at 22 to 24%).

The interesting part is what happens after the conversion. Programs like Subscribe & Save rely on recurring orders for exactly these types of products. Consumers stocking up on everyday items during Prime Day often opt into subscriptions, turning a one-time conversion into long-term repeat revenue. Bidding logic that optimizes only for that initial sale misses where the actual lifetime value gets built.

What this means for 2026. Treat Prime Day as a subscription acquisition event. AI can model the subscription halo. Humans need to point the model at it as an objective in the first place, otherwise it’ll keep optimizing for the wrong thing.

Conclusion: AI or not AI?

Look at the seven shifts together and a pattern emerges. Brands in 2025 spent smarter across nearly every lever, with better creative, better targeting, better pacing, and a sharper format mix. That kind of operational sophistication isn’t possible without AI doing real work in real time. But the wins originate in human decisions: creative direction, product data quality, audience definition, format portfolio, category investment, subscription strategy. AI compressed the cost of execution. Humans defined what to execute.

That division of labor will sharpen through 2026, and it’s exactly the topic of Skai’s upcoming webinar on May 28, To AI or not to AI: Amazon Prime Day and Walmart Deals Day. A panel of practitioners will work through pre-event, during-event, and post-event scenarios where AI accelerates the work, and where it doesn’t. If you’re planning Prime Day 2026, that’s the conversation worth being in the room for.

Skai’s Retail Media solutions enable marketers to plan, activate, and measure campaigns across 200+ retailers, including Amazon, Walmart, Target, and Instacart, as part of a broader commerce media strategy. AI-powered pacing, product intelligence, and keyword tools help teams meet shoppers across the journey and tie spend to sales with confidence.

Ready to see what these shifts could mean for your 2026 plan? Schedule a quick demo.

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