If a company's success can be linked with its CEO's popularity, then Twitter is going to have a very bright future. New rankings concerning Silicon Valley CEOs are out, and Dick Costolo, who replaced Twitter cofounder Evan Williams in October, came in first place. It's of course possible to like a clueless person or respect someone who's a jerk, so we're not really suggesting anyone put too much stock in these findings. Still, they may at least influence how well different companies can hold onto talented employees.