In the recent case of Eva's Bridal Ltd. v. Halanick Enterprises, Inc., Judge Easterbrook of the Seventh Circuit highlights the importance of managing a license of a registered trademark.
One of the reasons that one applies for and obtains a trademark registration is to show ownership---instant identity---of a good or service. When one sees or hears the mark coca-cola, the company Coca-Cola comes instantly to mind. That's the point. To ensure the continuity of that association, Coca-Cola must monitor the use of its trademark to ensure that no one is using it without right. Why? Well, Coke wants to make sure it gets paid for the use of its valuable trademark. But it also wants to make sure that Coke products are of good quality. If it licensed its trademark to a producer of poor quality soda, the consumer might associate bad soda with Coke and avoid Coke products in the future. Also, on some level, the consumer has an expectation that buying a Coke product will yield a Coke-quality product. Therefore, Coke will make sure that any company producing Coke products will do so under its strict rules to ensure consistent quality.
Sometimes, though, trademark holders are happy enough to pocket their licensing or royalty fees, but ignore their obligation (yes, obligation) to maintain a role in the production of the goods being sold under the trademark. That's called naked licensing. And its a good way for a trademark holder to lose its trademark registration.
In his decision, Judge Easterbrook refused to accept the theory that naked licensing is OK if the licensee is a "high quality" business and a trusted partner to the trademark owner who licensed the trademark. Because the reputation of the trademark owner (the licensor) is "at stake in every outlet," the consumer has a right to expect that the goods purchased under the trademark is reviewed for the quality and delivery that the consumer expects.
So, while a trademark is often seen as protecting its owner's business, preventing unauthorized use by competitors, ultimately, that is done to ensure that the consumer receives goods or services consistent with what it comes to expect from the trademark holder. If I buy a Coke, I should expect to get a Coke.