The Third Edition of this full-length treatment of the law of trademarks in the United States begins by presenting a thorough discussion of why we protect trademarks. It delves into the theoretical justifications that support trademark protection, including law and economics, notions of freedom of competition, and cultural justifications. The book is unique in the field in that it presents trademark infringement early rather than later in the semester. The idea behind making infringement an early subject is that all of trademark law was originally a common-law subject. As such, it was all judge-made and cases arose only when someone sued someone else for trademark infringement. Congress stated that the Lanham Act (America"s trademark law) was a codification of the common law of trademarks. Therefore, the law of trademarks is put in the correct historical and theoretical justification. Additional chapters focus on obtaining trademark rights, retention of trademark rights, registration of trademark rights, and loss of trademark rights. This Third Edition also provides an updated education on the current status of Trademark Dilution Law and the new and various causes of action regarding domain names. No other textbook on the market provides such comprehensive coverage of these two timely topics in Trademark Law.