Six days.
That's the window between now and Prime Day June 23–26. If you sell on Amazon and haven't opened your ad account this week, there's a good chance two costs are running higher than you think: one that's been climbing all year, and one that's been billing since March without so much as a notification.
The CPC problem is real and documented
Amazon Sponsored Products CPC averaged $0.89 in 2023. By early 2026 it was $1.21 — a 35% climb over three years — and the June print is sitting above that on category head terms.
Three forces are stacking before Prime Day. Alexa for Shopping (formerly Rufus) concentrates discovery impressions onto a narrower set of head terms, which compresses the auction into fewer placements. Amazon's Bid+ overhaul changed how maximum bid adjustments work, redrawing the math that most sellers built their 2024–2025 campaign structures around. And then there's just the event itself: top keyword CPCs are expected to hit $2.50 to $8.00 during Prime Day, roughly double to quadruple where things sit today.
If your daily budgets and bids haven't been updated in the last 30 days, they're calibrated to a market that no longer exists. Campaigns running fine in May will exhaust their daily caps by mid-morning on June 23.
What changed in March
Amazon's Sponsored Products and Sponsored Brands Prompts exited open beta on March 25, 2026. Before that date, they were free. Clicks on AI-generated prompts surfaced inside Alexa for Shopping conversations cost nothing during the beta period. After March 25, every click on a Sponsored Prompt bills as CPC, charged under the exact same bid parameters as the parent campaign.
There's no separate bid for prompts. The click goes against whatever your campaign is currently bidding in that category at that moment. Every eligible Sponsored Products and Sponsored Brands campaign was auto-enrolled; you didn't opt in, the feature went live, and it has been running ever since.
If your campaign is winning competitive auctions at $2.40 CPC, your Sponsored Prompt clicks are coming through at that same rate. Whether that cost is justified depends on how the placement actually converts in your category, but most sellers haven't pulled the numbers to find out.
How to find your actual numbers
Placement reports in Amazon Ads show Sponsored Prompts as a separate line item. Pull it. Compare the CPC and ACOS on that line against your campaign baseline.
Some sellers find prompt placements convert better than standard positions. Users who interact with Alexa before clicking have already engaged with a recommendation, so intent tends to be higher. Others find the opposite: elevated CPC, thin conversion volume, poor ACOS relative to the rate they're paying. The pattern varies by category.
If the placement is underperforming, you can apply a negative bid adjustment to it using the same placement modifier controls you'd use for top-of-search versus product page positions. This limits exposure without pausing the underlying campaign. The lever exists; most sellers just haven't looked for it.
Six days out: what to actually do
Raise daily budget caps on your top-performing campaigns. Prime Day CPCs will spike 60–80% above where they are right now. A campaign running well on $150/day will run out before noon on June 23 without an adjustment.
Don't launch new campaigns. Anything started this week won't exit learning before the event opens. Put budget into campaigns that have already established a history.
If you're running fewer than three formats, add the missing one now. Sellers running Sponsored Products, Sponsored Brands, and Sponsored Display together see 139% more sales than those running a single format. A conservative budget on the third format is better than not having that footprint during the four highest-volume days of your Amazon year.
Pull the placement report and check your Sponsored Prompts line specifically. Know the CPC, know the ACOS, and decide about bid adjustments before June 23, not during it.
It compounds
A record-high baseline CPC, plus an auto-enrolled AI placement billing at campaign rates, plus demand that will double or triple click costs during the event: these don't just add up. They multiply. The brands that come out of Prime Day with acceptable economics will be the ones who went in knowing their actual per-placement cost structure.
If you want to see how your account looks heading into the event, the free Gromerce audit surfaces spend efficiency gaps in about three minutes.
Amazon just made Prime Day more expensive through several mechanisms at once — knowing your real numbers before June 23 is the only structural advantage you can still build in time.
Sources: Novadata, ppc.land, Autron, ecomclips.com, Amazon Ads, June 2026
