Many people confuse selling a trademark with selling an idea or a name, in the same way that Internet domain names are often registered speculatively and then sold. With trademarks, what is being sold is not only the name of the product or business, but also the goodwill associated with that name.
What is a Trademark?
Trademarks are only valid for the same type of product, so if a company makes a line of clothing under the "BlueButton" trademark, a software developer could sell "BlueButton" software without infringing on the trademark of the clothing company. This may serve to limit the market for a given trademark. To add to the complexity of the situation, trademarks can be registered in different localities, or even be unregistered, while still existing as valid trademarks. In the United States, trademarks are registered with individual states or with the U.S. Patent and Trademark Office, depending on the geographic region in which the trademark is used. Now, on to how to sell a trademark.
In how to sell a trademark, the first step is to identify potential customers. Sometimes this is easy, such as in the situation where you have been running a successful business with considerable name recognition in your city and would like to retire. Possible customers would include your competitors and your employees, either of whom might be interested in continuing to sell products under the same name. The sale would typically include other aspects of the business such as its customer list and physical assets. Including other assets of the business in the sale is a way of assigning the goodwill associated with the trademark to its new owner, and also serves to increase the value of the transaction. If you are not sure who might be interested in buying your trademark or need help estimating its worth, there are companies specializing in the sale and valuation of intellectual property who will be able to help. The actual transfer, or assignment, of a trademark requires documentation typically prepared by a lawyer. Once these documents are completed, they can be easily used to register the assignment of the trademark with the appropriate government entity.