A lot of it is about brand. First impressions matter. I'm old enough to remember when Facebook launched with an actual emphasis on privacy. You couldn't even j

A lot of it is about brand. First impressions matter. I'm old enough to remember when Facebook launched with an actual emphasis on privacy. You couldn't even join Facebook as a random person from off the street -- you had to be a Harvard student, then a college student, then a student of some kind. It took some time for the service to open up to the general public at all. Then even at that point (as far as I can tell; I was never much of a Facebook user) your content was more restricted to your immediate circle of friends than it is today. And, of course, friend lists were naturally smaller in those days. When Facebook changed their privacy defaults, it tended to happen gradually, without much fanfare except for revolts among the relatively small number of cognoscenti who knew about the obscure settings screens that most users never even visit. In other words, Facebook successfully seduced people into trusting them, by starting out smaller and more constrained than they are today, and by almost always speaking with a human voice -- generally, the voice of your good friend who has just invited you to Facebook. Google, on the other hand, started out as the friendly-but-distinctly-nonhuman omniscient robot who has read everything and indexed everything and can answer any question about anything. Then it watched all our YouTube videos and scanned all our books and memorized all our maps, and it helpfully filed all our email for us, and it got some spy satellites and photographed all of our backyards, and it grew eyes and drove around the city capturing pictures of our buildings (along with the occasional embarrassed passerby). And only then, after it had established a very strong reputation as the super-powerful arbiter of all world knowledge, including knowledge of every one of us, did the Googlebot throw a party, invite us, and ask us all -- using a voice carefully designed by a team of top-notch professionals -- to be its friend. And to speak clearly into the microphones, so that the after-party analysis team can get a clear transcript of everything we say. It's all in the delivery.