... rights to a trademark can be acquired in one of two ways: (1) by being the first to use the mark in commerce; or (2) by being the first to register the mark with the U.S. Patent and Trademark Office ("PTO"). ...
(1) The use of a mark generally means the actual sale of a product to the public with the mark attached. Thus, if I am the first to sell "Lucky" brand bubble-gum to the public, I have acquired priority to use that mark in connection with the sale of bubble-gum (assuming that the mark otherwise qualifies for trademark protection). This priority is limited, however, to the geographic area in which I sell the bubble gum, along with any areas I would be expected to expand into or any areas where the reputation of the mark has been established. So, for example, if I sell pizza in Boston under the name "Broadway Pizza," I will probably be able to prevent late-comers from opening up a "Broadway Pizza" within my geographic market. But I will not be able to prevent someone else from opening a "Broadway Pizza" in Los Angeles.
(2) The other way to acquire priority is to register the mark with the PTO with a bona fide intention to use the mark in commerce.