At a high level of generality, intellectual property (IP) regimes are much alike. They grant exclusivity to promote socially desirable activity, be it creating goodwill and maintaining quality, producing expressive works, or inventing technological products and processes. Of course details differ, for each system must take account of the demands of the sector it governs. Thus the gravamen of a copyright claim – copying – would never be suitable for trademark law because trademark’s focus on diminishing search costs is inconsistent with allowing similar trademarks (even if independently produced) to confuse consumers. Similarly, trademark’s term of protection – which continues as long as the mark is in use – would not be suitable for patent law, where one generation’s output is the next generation’s input and the goal is to promote rapid progress.