The Madonna theory states, roughly, that all publicity is good publicity. Corollary: There is no such thing as bad publicity. (Other Madonna theories here.)
Professional public relations people protested, but to no avail. Paris Hilton enthusiastically adopted it (although Paris is smart enough to always be very, very nice to photographers). So did the trainwreck crowd (Lindsay, Britney, Ashley, etc).
But such ‘priceless’ worldwide publicity hasn’t helped Don Imus (although I’m cynical enough to say ‘yet’). Even the Material Girl’s thick skin was pricked; she blamed the press, but she could have communicated her adoption story with more grace.
The take-away: Know your story, work out your messages–and watch what you say.