The Ad Optimizer now supports bid adjustments for Sponsored Products and Sponsored Brands campaigns. This allows you to adjust bids for a selected audience either created in the Amazon Marketing Cloud (AMC) or provided by Amazon, as well as for selected ad placements. Bid adjustments are optional and can be made for each type separately during campaign creation or during updating. 

Placement
Placement bidding enables you to set bid adjustments for different placements,depending on the campaign type.

Sponsored Products*: Top of search, Product page, Rest of search
Sponsored Brands: Placements other than top of search

"Ad Optimizer automatically pre-populates the placement settings with default values ("Top of Search + 50%" for targeting types Keyword and Amazon auto and "Product Page + 50%" for targeting types Product and Category). These values can be changed.

Audiences
With audience bid adjustments, you can target customers in a specific audience who, for example, clicked on a specific product but did not purchase it, and then selectively modify the bids for that group in your campaigns.

How to set bid adjustments in Ad Optimizer?
Bid adjustments can be set either during campaign creation or by editing a campaign inline in the Campaigns table. A click on the “Bid adjustments”-icon opens the modal where settings for Placement and Audience can be made.
Bid adjustments are currently configurable solely through the Ad Optimizer frontend. The functionality for bulk import files will be introduced in the near future.