Now that one of the world’s earliest search engines and email portals is about to have its identity subsumed by Verizon and its rump reduced to an investment management company, it is worth wondering how a former giant, once a potent symbol of Silicon Valley’s dynamic entrepreneurship, became a wan midget in 22 years, a remarkably short lifespan even by the standards of technology companies. Yahoo’s obituary was, in fact, being written all over the US business press as early as 2015 and, no surprise, management bible Harvard Business Review has already produced a potted case history of its decline.