Those who are calling Twitter a fad are missing the point. Twitter is simply a very effective "one to many" communication medium. Twitter as we know it will certainly pass, either evolving or being superseded by something else. Does that mean individuals and business should not be investing time and resources building their presence on it? No. Does that mean that it has disrupted how we communicate and congregate across geographical boundaries? Yes. Will understanding and building strategies around Twitter hold you in good stead for "the next big thing"? Yes.