Some people tend to chose long URL's for the sake of getting a ranking in the keywords listed in the URL, unfortunately there is no evidence of this being good, in fact it is really bad on the side that users will not remember your URL anyways and sometimes they will be too lazy to type it in in the first place.

As you may have already seen on (16 - Keywords in the URL) The method of including keywords in your URL is usually not the way to go.

Even more, when your website's name is too long people will not be coming by typing your URL, that means you will probably be less popular leading to a lower ranking on search engines.