Amazon PPC fails most often because the account is a pile of campaigns, not a system. Structure should follow the listing: defend what already converts, harvest search terms from auto, then scale exacts that prove ROAS.
Split branded, competitor, and generic intent. Mixing them hides whether you are buying your own name cheaply or overpaying for cold traffic. Give each intent its own campaign with budgets you can actually read at a glance.
Use auto and broad to discover, not to scale. Harvest converting queries into exact match, negate the junk, and keep discovery budgets small. Exact is where you put real money once the listing conversion rate can support it.
Match bids to the funnel, not to a single ACOS target across the catalog. A hero SKU with a strong listing can take a lower ROAS in exchange for rank. A weak listing should not get aggressive bids — fix the page first.
Review search term reports weekly, placements monthly, and catalog winners quarterly. PPC is not a set-and-forget channel. The brands that compound are the ones whose structure still makes sense six months later.