Registration of your trademark at the state or federal level has several advantages, not least of which is the legal advantage that will be yours if you have to file an infringement action. A registration of your mark is evidence of your claim of ownership of it, and once registered your mark will appear in availability searches conducted by others. This is very important given the nationwide reach of a federal registration. Whenever anyone conducts a search of the same or similar marks, they will instantly find your mark and be discouraged from pursuing the mark any further.
This simple process, unseen by you, could potentially save you many thousands of dollars in an infringement lawsuit, which would be necessary if the new user were unaware of your rights.
If your business and its goods and services are, and will continue to be, limited to a single state, you may need only a state registration. But if your goods or services travel in interstate commerce or foreign trade, then you should have a federal trademark registration to protect your rights. A trademark attorney is not indispensable to this process, but can be very helpful.
In addition to the advantages already mentioned, a federal registration gives you presumed nationwide rights in the mark dating back to the time you filed the application. Your federal registration means that the federal courts have jurisdiction to hear infringement and related unfair competition claims on your behalf. A federal registration can also be recorded with the U.S. Customs office to prevent importation of goods bearing marks that infringe yours. And, your "mark" can become incontestable -- meaning you will have significant legal advantages in enforcing your trademark rights -- five years from the date of its registration.
Safeguarding your trademark rights protects not only your name or logo, but the goodwill that is associated with your business. If all of Coca-Cola's physical assets disappeared today, the company would still own its most valuable asset -- the Coca-Cola trademark -- currently valued in excess of $30 billion.