How to read these pages
Every factual claim carries one of four labels:
A number can be true and still be specific to its sample: a measurement on a few stores in one month is evidence, not a law. When two sources disagree, each page prints the most recent measurement on the largest sample and says what it was.
Five things most advertisers get wrong
- A bid mostly buys entry, not a better price. Raising a bid wins far more auctions than it changes where the ad lands or what a click costs. See The Auction.
- Many clicks are charged the full bid. Amazon’s auction does not behave like the clean “pay just above the next bidder” auction most guides describe. See The Auction.
- Organic clicks fall smoothly down the page. There is no cliff after the first row: each place lower loses a little, and beyond the top ten the click rate sits on a low floor. See Organic and Paid.
- Every demand source ranks searches well and counts them badly. Each one is reliable for which search is bigger, not for how big. See Demand and Markets.
- Nobody has measured how much paid sales lift organic rank. It is the most common belief in the industry, and ours too; it is still a hypothesis. See Organic and Paid.