Inset Systems, Inc. (Inset) (plaintiff) is a computer software company incorporated under the laws of Connecticut. Instruction Set, Inc. (ISI) is a computer technology company incorporated in Massachusetts. In 1985, Inset secured a federal trademark for its business name: INSET. Some time after that, ISI established INSET.com as its Internet domain address and began advertising its products worldwide. The Internet is a worldwide, electronic communications network connecting some 20 to 30 million users, at least 10,000 of which are in Connecticut. Internet users are able to locate other users through domain addresses. This means that Internet users may be confused when one company uses another’s trademarked name as its domain address. Further, Internet advertisements are available to all users simultaneously and continuously, unlike television, radio, and newspaper ads. In addition, ISI advertises to customers using the toll-free telephone number “1-800-US-INSET.” Inset filed suit against ISI for trademark infringement, unfair competition, violations of the Connecticut Unfair Trade Practices Act, and other claims in the United States District Court for the District of Connecticut. ISI moved for dismissal under Federal Rule of Civil Procedure (FRCP) 12(b)(2) on the ground that the court lacked personal jurisdiction.