Amazon PPC glossary
Bid multiplier (Placement Adjustment)
A percentage increase applied to your base bid for specific placements such as Top-of-Search or Product Pages.
Where it matters most: Book 1, The Amazon PPC Clarity Guide, in the chapter “Bid Optimization.”
Go deeper
The glossary gives you the one-line answer. The Amazon PPC Clarity Guide explains why it matters and what to do about it.