Why register a federal trademark?
A trademark registered with the federal government carries a number of advantages over one that has not been registered.
First, only federally registered trademarks can be enforced in federal court – so if someone is using your mark illegally, you can use the federal courts and federal law to get them to stop.
Second, if you’re successful in such a lawsuit, you may be able to get damages for their use of your trademark.
Third, if you register your mark federally, you are presumed to have used it across the entire nation and thus are presumed to have superior rights over anyone else that starts to use the mark after you.