What's the quickest way to ruin a friendship? Do great friendships have anything in common? Are close friendships in the workplace such a bad thing?These are just a few of the questions that #1 New York Times bestselling author Tom Rath asked when he embarked on a massive study about the impact of friendships. Along with several leading researchers, Rath pored through the literature, conducted several experiments, and analyzed more than 8 million interviews from The Gallup Organization's worldwide database.His team's discoveries produced Vital Friends, a book that challenges long-held assumptions people have about their relationships. And the team's landmark discovery - that people who have a "best friend at work" are seven times as likely to be engaged in their job - is sure to rattle the structure of organizations around the world.