Is an attorney's LinkedIn profile an advertisement?

Legal Ethics in Motion is reporting that the Association of the Bar of the City of New York Committee on Professional Ethics'  Formal Opinion 2015-7 concludes that if the primary purpose of an attorney’s LinkedIn profile is not to attract new clients, it is not advertising.  I understand the idea, but I am not sure I understand how it applies in reality.  If the profile is about a lawyer and his or her practice, is there really any other purpose for having a profile in LinkedIn?