Amazon PPC glossary
Cannibalization
Cannibalization happens when two of your own campaigns compete for the same keyword. You bid against yourself, which can push up your cost and make your data harder to read.
Example
Your auto campaign and your manual campaign both show your ad for “bamboo cutting board.” Your own bids compete with each other, and you cannot tell which campaign earned the sale.
Where it matters most: Book 1, The Amazon PPC Clarity Guide, in the chapter “Campaign Architecture.”
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.