It’s a sad day in the world of marketing as the brewer of Dos Equis beer has announced its spokesman for the past nine years is about to impart on his final journey.The suave, bearded character known only as “The Most Interesting Man in the World” is being retired. Apparently, he’s not so interesting anymore.I mention this story to convey the power of advertising and what a catchy ad campaign can do for a business. Since the debut of “The Most Interesting Man,” Dos Equis has nearly tripled its sales, according to company VP of marketing Andrew Katz.