What is Campaign Bidding Strategy?
Amazon Campaign Bidding Strategy
The campaign setting that decides whether Amazon may lower, raise or leave alone the bid you set, at auction time.
The Formula
Effective bid ≈ Base bid × (1 + Placement modifier) × (1 ± Dynamic adjustment)
Campaign bidding strategy is the campaign-level setting that decides how much freedom Amazon has to change your bid in the auction. It is not a bid and it is not a budget. It is a permission.
The three settings
| Strategy | What Amazon may do | What it does to your control |
|---|---|---|
| Dynamic bids, down only | Lower the bid when a click looks less likely to convert | You keep the ceiling, Amazon removes some of the worst clicks |
| Dynamic bids, up and down | Lower it, and also raise it for placements where a conversion looks more likely | Your bid becomes a starting point, not a limit |
| Fixed bids | Nothing, your bid is used as set | Full control, no automated protection |
The difference that matters is the ceiling. Under up and down, the amount entering the auction can exceed the bid you priced from your margin, and the increase is applied by a system optimising for conversions rather than for your contribution margin. Amazon publishes limits on how far it will raise a bid, and those limits differ by placement, so read the current figures in your ad console rather than assuming them.
The compounding trap
This is the mechanism most often missed. Placement modifiers apply to the bid before Amazon's dynamic adjustment, so the two compound rather than add. If a tool also rewrites your stored bid on a time-of-day schedule, that is a third layer, and the layers multiply.
Effective bid ≈ Base bid × (1 + Placement modifier) × (1 ± Dynamic adjustment)
Worked example
Suppose a base bid of 50 pence and a top of search placement modifier of 100 per cent. The bid entering the top of search auction is 1 pound, not 50 pence. Now suppose a dayparting multiplier of 25 per cent has already lifted the stored bid to 62.5 pence for the evening. Top of search now enters at 1.25 pounds, and if the campaign runs up and down, Amazon's upward adjustment applies to that 1.25 pounds rather than to your original 50 pence. Three settings that each look moderate can more than double the bid entering the auction.
Note that the bid is a ceiling, not a price. What you are charged for the click is settled by the auction and is normally lower, which is exactly why the next rule exists.
Our house view
We favour bids you set, with down only as the tolerable exception, because a bid computed from your break-even is a decision, and handing its ceiling to the platform undoes that decision quietly.
- Price from realised cost per click, never from the bid. The bid is a setting; the CPC is a fact. Under dynamic bidding the two are routinely different, and the gap is exactly what you need to see.
- Choose placement modifiers on relative conversion rate, not on placement ACoS. Placement ACoS mixes the keyword's bid in with the placement's quality, so a placement that converts best can look expensive and still deserve the highest modifier.
Set the base bid to the economics of the weakest placement, then raise the better placements with modifiers.
Examples
- →A 50p bid with a 100 per cent top of search modifier enters that auction at 1 pound
- →Comparing realised CPC against the bid you set, to see what dynamic bidding is doing
- →Setting the base bid from the worst-converting placement, then raising the rest with modifiers
Related Terms
Bid Optimization
The process of adjusting keyword bids to maximize profitability.
Dayparting
Adjusting ad bids or budgets based on time of day or day of week.
CPC
Cost Per Click - the amount you pay each time someone clicks your ad.
ACoS
Advertising Cost of Sale - measures ad spend as a percentage of ad revenue.
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