Entrepreneur and investor had already founded a small handful of companies when he began his best-known role, as chief executive of . He'd networked his way into Silicon Valley by asking smart questions of successful people, including founders of such companies as Salesforce and Yahoo. Inc. asked several entrepreneurial luminaries like Libin to share a piece of . Here's one piece of advice so specific--and reliable--that Libin has come back to it many times throughout his career. --As told to Christine Lagorio-ChafkinProbably the came from Hiroshi Mikitani, who is the...…Entrepreneur and investor had already founded a small handful of companies when he began his best-known role, as chief executive of . He'd networked his way into Silicon Valley by asking smart questions of successful people, including founders of such companies as Salesforce and Yahoo. Inc. asked several entrepreneurial luminaries like Libin to share a piece of . Here's one piece of advice so specific--and reliable--that Libin has come back to it many times throughout his career. --As told to Christine Lagorio-ChafkinProbably the came from Hiroshi Mikitani, who is the...WW…