Organic sales

Amazon attributes a sale to an ad if the shopper clicked that ad within the attribution window before buying; everything else counts as organic. Organic share, typically 60 to 80 percent in healthy mature accounts, is the clearest sign that advertising builds rank rather than renting it.

Paid sales feed organic rank: sales velocity and conversion rate on a keyword push the product up in organic results. That halo is why a campaign can be worth running above its own break-even ACoS, and why TACoS tells the real story.