Most Amazon sellers are obsessed with ACoS. But ACoS alone is lying to you. Here's what I learned after managing £2M+ in Amazon UK sales in 2025: Two campaigns can have the exact same ACoS. One is profitable. One is bleeding money. The difference? ROAS at the ASIN level — not the account level. Here's the framework I use: 𝟭. Segment by margin, not just by category A product with 60% margin and 3x ROAS is more profitable than a product with 25% margin and 5x ROAS. Always map ROAS targets back to actual margin per ASIN. 𝟮. Kill the 'portfolio averaging' trap High-ROAS hero ASINs often mask 6-8 underperforming ones in the same campaign. Isolate them. Let heroes scale. Cut the dead weight. 𝟯. Bid by intent stage, not just match type Broad match for discovery. Exact match for conversion. Most accounts I've audited have these budgets completely reversed. 𝟰. ROAS floors, not ROAS targets A target creates anxiety. A floor creates discipline. Set the minimum acceptable ROAS per product tier and optimise above it — not around it. Applying this alone helped me improve ROAS while reducing ACoS by 20% — without cutting a single pound of ad spend. If your ROAS looks fine at account level but margins are shrinking, the problem is almost always in the structure — not the bids. Happy to break down any of these points further in the comments. ♻️ Repost if this helps someone running Amazon ads today. #AmazonPPC #AmazonAdvertising #ROAS #SponsoredProducts #AmazonUK #EcommerceGrowth #PPCStrategy #AmazonSeller