Amazon’s dominance of online retail means that small businesses have little choice but to rely on its site to reach consumers. This report finds that Amazon is exploiting its position as a gatekeeper to impose steep and growing fees on third-party sellers. Even as these exorbitant fees bankrupt sellers, they are generating huge profits for Amazon, a fact that the tech giant conceals in its financial reports. These profits are not only the spoils of Amazon’s monopoly power. They are the essential fuel that feeds its market-domination strategies, enabling it to absorb massive, predatory losses designed to lock-in market control and fund breakneck expansion.