Give David a break. First of all, he's a very nice guy. Secondly, he's not running a corner greengrocer, he's running a site that's growing supernaturally fast and which has completely, utterly displaced myspace as the place where high school kids share. Tumblr has five MILLION visitors every single day, almost none of whom pay a dime. You can't run a service like that the same way you run an enterprise software comp…
Do you really need a PR/CS team to ensure people get a nice reply? Shouldn't that just be something that a /very nice guy/ would accomplish naturally?