The first person to use a trademark in connection with specific goods or services preserves a common law right to prevent any unauthorized use of that mark with similar goods or services. However, federally registering your mark with the United States Patent & Trademark Office provides more protection than established under common law. In fact, an unregistered mark may only protect use of your mark within a specific geographical area, while a federal registration provides exclusive right to use of that mark nationally.
If your mark lacks federal registration, the ability to enforce your rights through legal proceedings may therefore be limited. In fact, a registration not only provides constructive notice of the mark to infringers, but provides right to sue in federal court with a legal presumption as to ownership of the mark. Additionally, federally registering your mark provides more remedies available against infringing parties. For instance, the registrant may recover up to triple damages and attorney's fees for any willful violations.
The rights established from a federal registration can last indefinitely, as long as the owner continues active use of the mark on or in connection with the goods and/or services in the registration. Therefore, registering your trademark provides a bundle of exclusive rights that are otherwise not available through common law use of the mark.