Steve Kaufer, co-founder, president and CEO, TripAdvisor. Before the label "blogosphere" ever appeared, Steve Kaufer had already defined its potential with TripAdvisor. The 25 million monthly visitors who read, opine, whine, praise and rant on his multiple sites make it the largest online travel community in cyberspace. And its power has all other travel sites and suppliers trying to manipulate ratings and land atop his link positions, and quaking in their boots that they'll be royally flamed.