Quick Answer: Your bidding strategy is not your bid. It is the permission you give Amazon to move your bid in the live auction. Three options exist: fixed bids, dynamic bids down only, and dynamic bids up and down. Each one changes what a single click can cost you, and picking the wrong one is expensive in a way that stays invisible for weeks.
Most brand owners find this setting once, during campaign setup, and never open it again. Then six months later the ACoS has drifted, nobody can say why, and the fix everybody reaches for is lowering keyword bids.
Which is usually the wrong lever.
The bidding strategy and the keyword bid do different jobs. The bid is what you are willing to pay. The strategy governs how far Amazon may move away from that number before it charges you. Changing one when you meant to change the other is one of the most common causes of a campaign that either stops spending entirely or quietly doubles its cost per click.
This guide covers what each strategy does, the widely-repeated figure that Amazon’s own documentation now contradicts, how placement adjustments interact with all of it, and what changed on 10 August 2026 that made a chunk of your bid settings stop applying.
What a bidding strategy actually controls
Sponsored Products are cost-per-click ads promoting individual listings, and Amazon runs an auction for every impression. You submit a maximum bid. The bidding strategy tells Amazon’s system what it may do with that number between the moment the auction opens and the moment you get charged.
Three things follow from that, and they are worth holding onto.
Your bid is a ceiling in some strategies and a starting point in others. Under fixed bids, Amazon applies the number you set. Under either dynamic strategy, Amazon adjusts in real time based on how likely it judges that impression is to convert.
The setting applies at campaign level. It covers every keyword and every target inside that campaign. You cannot run one keyword on fixed bids and its neighbour on down only without splitting them into separate campaigns, which is a large part of why account structure matters more than most bid tinkering.
And the strategy is not a performance dial. Switching from down only to fixed does not make a campaign perform better. It changes the shape of the risk. A campaign that is spending too much at a high ACoS and a campaign that will not spend at all are different problems, and they need opposite moves.
The three strategies, and what each does to your money
Fixed bids. Amazon does not adjust your bid based on conversion likelihood. You said £1.20, the auction sees £1.20. You get predictable cost per click and you lose the algorithm’s ability to pull back on impressions that were never going to convert. This is a control tool, not a savings tool.
Dynamic bids, down only. Amazon reduces your bid in real time when it judges a conversion unlikely, and never raises it above what you set. Your stated bid becomes a genuine ceiling. The trade-off is visibility: on competitive keywords, a bid that keeps getting shaded downward loses auctions you might have wanted to win.
Dynamic bids, up and down. Amazon raises the bid for impressions it thinks will convert and lowers it for the ones it does not. This is the aggressive setting, and it is the one people select without reading what it permits.
Here is the part that matters for your P&L. In Amazon’s own guide to dynamic bids up and down, the company states that it will increase or decrease bids by up to 100% for all placements based on performance, and gives a worked example: a $1.00 bid can go to a maximum of $2.00. The guide’s own advice is blunt about the consequence. Be prepared to potentially spend double the amount of the bid you input.
That is the sentence to read to whoever set your bids. If your budget model assumed £1.20 clicks and the campaign is on up and down, the model needs to assume £2.40.
| Amazon adjusts your bid | Your bid is a ceiling | Best suited to | |
|---|---|---|---|
| Fixed bids | No | Yes, by definition | Proven keywords where you know the profitable CPC and want it held |
| Down only | Lowers only | Yes | New launches and cost control, where overspend is the bigger risk |
| Up and down | Raises and lowers | No | High-performing campaigns where you can fund double the stated bid |
The 50% figure a lot of guides still quote
Search for this topic and you will find articles published in 2026 stating that up and down raises bids by up to 100% for top of search and up to 50% for everywhere else.
Amazon’s current guide does not say that. It says up to 100% for all placements.
We are not claiming Amazon announced a change, because Amazon did not announce one that we can find, and asserting a rollout that may not have happened would be exactly the kind of confident error this industry runs on. What we can say is narrower and more useful: the primary source and a good deal of the secondary coverage disagree, and the primary source is the one that governs your invoice.
This is worth a minute of your time rather than a shrug. If you built a Q4 budget on the assumption that only top-of-search bids could double, and in fact any placement can, your worst-case spend is materially higher than the number in your spreadsheet. Open Amazon’s guide, read the section headed “If I have a bid of $1.00, how much could I spend?”, and model from that.
The wider lesson applies to everything in Amazon advertising. Ad platforms change quietly and blog posts do not update. Anything involving a percentage, a cap or a threshold should be checked against Amazon’s own documentation for your marketplace before it goes into a plan.
Placement adjustments sit on top, and the order matters
Separate from the bidding strategy, you can raise bids for specific placements: top of search, rest of search, and product pages. These are the adjustments in the campaign settings that most accounts leave at zero and then forget.
They stack with the bidding strategy rather than replacing it. The widely-reported reading, consistent across practitioner guidance and Amazon’s help documentation, is that the placement adjustment applies to your base bid first, and the dynamic adjustment is calculated on the result. So a base bid with a placement uplift, then a dynamic increase on top of that, compounds into a number well above what anyone typed into the box.
Worth confirming against the bidding help page for your own marketplace before you set anything aggressive, because this is the interaction that produces the surprise invoice.
The practical version for a brand owner: if you are running up and down and you have also set a large top-of-search adjustment, you have authorised two multipliers on the same click. Most accounts that come to us with an unexplained CPC spike have exactly this combination, set at different times by different people, neither of whom knew about the other.
For a proven, profitable keyword, fixed bids with a placement adjustment is usually the more controllable structure. You get the placement uplift you wanted without also handing over real-time discretion. It is the approach we default to when we take over Amazon PPC management on an account with a spend history worth protecting.
What changed on 10 August 2026
Your bid settings no longer apply uniformly to every click you pay for, and this is recent enough that most accounts have not caught up.
Amazon Ads revised its off-Amazon advertising support article on 4 August 2026, adding creators to the list of destinations where Sponsored Products can run, with PPC Land reporting an advertiser notice setting 10 August as the start date. Existing campaigns were enrolled by default, at existing bids and budgets, with no advertiser action required.
The bidding rules for those placements are where it gets operationally sharp:
- Your maximum bid applies to all clicks, on Amazon or off it.
- Bid adjustments for Top of Search and Product Pages do not apply to off-Amazon placements.
- Dynamic bidding and the other bidding strategies do apply.
- Every off-Amazon click counts against the same campaign budget as your search clicks.
Read that second and third point together. The lever you use to control where your money goes has stopped working on part of your inventory, while the lever that lets Amazon spend more of it still works everywhere. If you have been managing placement mix through adjustments, that control is now partial.
There is a reporting consequence too, and it is the one that will confuse people for months. On off-Amazon placements with no search context, Amazon infers a search term and reports it. Those queries appear in your search term report despite no shopper having typed them. They are eligible for negative targeting, which is useful, but it means the report you use to make harvesting decisions now mixes observed intent with system-generated descriptors.
One detail for UK sellers specifically: the country list on Amazon’s support page covers Brazil, Canada, India, Mexico, the United States, the Middle East, North Africa and Turkey, and select EU countries. The United Kingdom does not appear on it. If you run UK campaigns only, this may not touch you at all. If you run US and UK from the same account, your two marketplaces are now operating under different rules, and comparing their placement data as though they are equivalent will mislead you.
How to choose: the order to work through
Do this in sequence. Skipping to step four is how accounts end up in the state described above.
- Pull the placement report first. Campaign manager, under Measuring and Reporting. Look at the last 60 days. You need to know where your spend actually goes before deciding what to adjust.
- Compare 1 to 9 August against 10 to 20 August if you advertise in an affected marketplace. That window isolates the change. If a meaningful share of spend moved to off-Amazon placements, that is your first conversation.
- List every campaign’s current bidding strategy. Most accounts have never audited this. Expect to find campaigns on up and down that were set that way during a launch two years ago and never revisited.
- Match strategy to campaign purpose. New launch with unproven keywords: down only. Proven exact-match keyword with a known profitable CPC: fixed bids. High performer you are deliberately scaling and can fund at double the bid: up and down.
- Check the off-Amazon setting. Under campaign settings, the section for ads served off Amazon offers “Increase reach”, which is the default, and “Limit off-Amazon spend”. Decide deliberately rather than inheriting the default. For accounts above a handful of campaigns, Amazon added an off-Amazon ad serving column to Sponsored Products bulksheets on 8 June 2026 for US advertisers, so this is an edit-and-upload job.
- Watch CPC and conversion rate separately for two weeks. A flat ACoS can hide cheaper clicks converting worse. If CPC falls while conversion rate falls further, cheap traffic is diluting quality.
- Check contribution margin, not ACoS. A click that looks fine on ad metrics can still be unprofitable on a SKU carrying high FBA and referral fees.
Amazon’s own guidance suggests reviewing bids roughly once every two weeks, and its Sponsored Products best practices guide covers the targeting and budgeting side that sits around this. That cadence is about right. Monthly is too slow to catch a drift before it costs you a month of margin.
What not to do
Do not switch everything to fixed bids in a panic. Fixed removes Amazon’s ability to pull back on impressions that were never going to convert. On a broad-match campaign with loose targeting, that gets expensive fast. Fixed suits keywords you have already proven.
Do not treat lower ACoS as the goal. You can drive ACoS down by killing volume, and the business gets smaller while the dashboard looks better. Total advertising cost of sales against total revenue is the number that reflects reality.
Do not blanket-negative the inferred search terms. They are descriptors attached to browsing impressions, not junk by definition. Judge them on spend and conversion like anything else.
If your account is under roughly ten SKUs and a few hundred pounds a month in ad spend, this is not your first problem. Bidding strategy optimisation on a small account moves very little money. Your listing conversion rate moves more, and it moves it on organic traffic too. We wrote about that in the guide to writing an Amazon listing that converts rather than just ranks, and it is the better place to spend a week.
One more honest limit. Creator placements send shoppers to your product detail page, which means your images, claims and pricing get inspected by an audience arriving with less purchase intent than a search click. If your creative is dated, that traffic will convert badly and the bidding strategy will get the blame. That is a product creative and brand asset problem wearing a PPC costume.
Frequently asked questions
What is the best Amazon Sponsored Products bidding strategy?
There is no single best one, and any guide claiming otherwise is selling something. Down only suits launches and cost control. Fixed suits proven keywords where you know the profitable cost per click. Up and down suits campaigns you are deliberately scaling with budget to absorb double the stated bid. Match the strategy to what the campaign is for.
Does changing my bidding strategy reset my campaign?
No. Changing the strategy in campaign settings does not delete history, targets or performance data. Amazon’s systems do take time to respond to the new setting, so give it at least two weeks before judging the result, and avoid changing several things at once or you will not know which change did what.
Why did my CPC jump without me touching my bids?
Common causes, in the order worth checking: a bidding strategy set to up and down combined with a placement adjustment, increased competition on your keywords, a seasonal auction shift, or a new placement type entering your mix. Since 10 August 2026, off-Amazon inventory including creator content is a genuine fourth candidate in affected marketplaces.
Do placement bid adjustments still work?
On Amazon, yes. On off-Amazon placements, Top of Search and Product Pages adjustments do not apply, according to Amazon’s off-Amazon advertising documentation. Dynamic bidding strategies still apply everywhere. This split is new as of August 2026 and it is the main reason to re-read your settings.
How do I stop my ads showing in creator content?
Amazon’s published controls are campaign-level. The “Limit off-Amazon spend” setting restricts offsite delivery, advertisers can exclude specific creators, and a deny list covers third-party sites and apps. Nothing in the published documentation describes an account-level switch that removes creator inventory outright. Check your own account notifications for the settings available in your marketplace.
Should I use fixed bids for a product launch?
Usually not as the first move. Down only lets you test keyword and ad combinations cheaply while Amazon shades away the impressions unlikely to convert. Fixed bids make sense at launch only when a campaign on down only is failing to spend and win any visibility at all, which does happen on competitive keywords.
Where this leaves you
The bidding strategy is a small setting with a large blast radius, and August 2026 made it smaller and more complicated at the same time. The bid you set no longer behaves identically across every surface you pay for, and the control you had over placement mix now covers less ground than it did in July.
None of that requires a rebuild. It requires knowing what percentage of your spend sits on inventory you did not choose, and checking it on a schedule rather than after a bad month.
If your cost per click has moved this quarter and nobody can tell you which of these is responsible, send us the account for a free audit and we will pull the placement report and tell you where it went. If you want to see the shape of that work first, the Amazon case studies show the before and after on real accounts.
Accurate as of 24 August 2026. Amazon changes advertising settings and documentation frequently, and availability differs by marketplace. Your Seller Central and Amazon Ads account notifications are the authority for your own account, not this article.
