Can be huge. If you "own a domain," you can be a giant killer, a Goliath maker, and both. What if Google decided to put Shmoop.com on its front page for a week? (Larry, Sergey, we encourage this notion.) They'd "make" Shmoop.com as one of the most trafficked websites in the world…overnight.
Power comes with wealth and political influence as well. When the President comes to Silicon Valley, his dinners are usually with the CEOs of the big companies, many of whom were the founders. Okay, so maybe not as much power as the Big Guy in Charge, but if you're important enough to be deserving of a few hours of his time, it probably makes you pretty powerful too, right?