Amazon PPC glossary
High-low bidding
Setting an aggressive bid to win a placement quickly, then stepping it down once the position is established, rather than starting conservatively and raising bids over time.
Where it matters most: Book 5, The Advanced PPC Clarity Guide, in the chapter “Reaching for an Aggressive Tactic, or Staying Simple.”
Go deeper
The glossary gives you the one-line answer. The Advanced PPC Clarity Guide explains why it matters and what to do about it.