How it works
First off, this blog article (click here) can give you all the information available around Amazon's dynamic bidding feature.
Recommendations for New or Unoptimized Campaigns: Down Only
The less data Amazon has for your products, the less accurate their conversion predictions may turn out. For new campaigns, where the focus at first will be cost reduction (and keyword research), we suggest using down only.
The same goes for campaigns where you have not yet done any kind of optimization (ie. negative keywords, manage bids based on performance).
Recommendation for Optimized & well performing Campaigns: Up & Down
If a campaign has generated a lot of data and is already optimized to a large part, using Up & Down can help you become even more sales efficient.
Recommendation for new Campaigns with Aggressive Intent: Fixed
If you want to push new campaigns at all costs (for example to get early reviews or push keyword rankings), fixed is a good option to force Amazon use your (high) bid.
WIth Down only or Up & Down, the bids for untrusted campaigns might otherwise always be adjusted down by Amazon.
Bulk Change Bidding Strategy in Sellics
On the Campaign level of the Optimize tab, you can select and edit the bidding strategies of all of your campaigns:
Good Interplay between Automation Rules & Dynamic Bidding
Although Sellics is not aware of how many times a bid was de- or increased in realtime through dynamic bidding, or by how much, it will still make sense for the rules to, for example, decrease the base bid if the ACOS remains too high.
Amazon will then continue its live dynamic adjustments according to expected conversion rates, but based on the new base bid.