Amazon’s dominance as a platform is widely documented. But one aspect of that dominance has not received sufficient attention—the Amazon Brand Registry’s sweeping influence on firm behavior, particularly in relation to the formal trademark system. Amazon’s Brand Registry serves as a shadow trademark system that dramatically affects businesses’ incentives to seek legal registration of their marks. The result has been a surge in the number of applications to register, which has swamped the U.S. Patent and Trademark Office (PTO) and created delays for all applicants, even those that previously would have registered their marks. And the increased value of federal registration has drawn in bad actors who fraudulently register marks that are in use by others on the Amazon platform and use those registrations to extort the true owners.

When we think about people seeking relief for infringement of their intellectual property rights under copyright and trademark laws, we typically assume they will operate within an overtly legal scheme. By contrast, creators of works that lie outside the subject matter, or at least outside the heartland, of intellectual property law often remedy copying of…