Qualifying Factors for Registering
The Slogan Should be Distinctive and Not Generic
A slogan that is too generic and is easily equated with a particular category of products or services will most likely be rejected. Any neutral phrase that describes the features of a product or service fails to qualify as distinctive. For instance, the USPTO (United States Patents and Trademarks Office) denied the registration of the slogan “Price Protection Guaranteed" to Norm Reeves, Inc. of California, because it is a commonly used informational phrase in the retail business.
It Should Not be Informational or Descriptive
A slogan that describes a certain product or conveys a message cannot be registered as a trademark. Rug Doctor, a firm that manufactures carpet and rug cleaning machines applied for getting their slogan “With a Vibrating Brush" trademarked, but the USPTO rejected their application on the grounds the slogan was simply informational and it in no way distinguished the firm's equipment from the other similar equipments in the market.
How and Where the Slogan is Used
A slogan has to be unique and it must identify the source of the goods or service, and not just be used casually in the advertising material. Panera Inc, a restaurant business, was denied approval for their slogan “You Pick Two", because the USPTO alleged that these were common words that were repeatedly used in their menus and advertisement material and in most cases, the words blended so well into the surrounding text they failed to grab attention.
The Slogan Must Indicate the Source
Simply having your slogan displayed on the goods will not convince the USPTO to trademark your slogan. Instead the slogan should indicate or identify the source of the product or service. If people associate your slogan deeply with your business, to an extent that if the same slogan were to be used by some other company it would leave them confused, then your slogan stands a better chance of being accepted and registered.
These qualifying factors have a lot of gray areas, and can leave anyone confused as to whether their slogan can really make it through the USPTO office. If in doubt, you must seek professional help from a business lawyer before proceeding further with your application.