In the early 2000s, Silicon Valley-based business guru John Hagel III was involved in a high-tech start-up and hired Stephen Gillett, a young man right out of college. Less than a half dozen years later, Gillett was named a senior vice president and chief information officer for Starbucks — the youngest CIO of a Fortune 500 company at that time. And Hagel thinks he knows a primary reason for his one-time employee’s meteoric rise. Everything that Gillett needed to know, Hagel said, he learned while becoming a guild leader in the popular online game World of Warcraft . The co-chairman of a tech-oriented strategy center for Deloitte LLP, Hagel told the annual Wharton Leadership Conference that Gillett — just like other top players on the massive online multi-player game, with an estimated eight million participants — reached out independently to build a large team of allies that solved complex problems and developed winning strategies.…