An oral history of LinkedIn, which turns 20 in May, as told by Reid Hoffman and its co-founders, current executives, Satya Nadella, Richard Branson, and others (Harry McCracken/Fast Company)

Harry McCracken / Fast Company:
An oral history of LinkedIn, which turns 20 in May, as told by Reid Hoffman and its co-founders, current executives, Satya Nadella, Richard Branson, and others  —  Social media, for work?  The world was skeptical.  But 20 years and a few white-knuckle moments later, LinkedIn has become synonymous …