Or does it "feel" like I know you? I often get asked for favors which either tap my time or perceived influence. I can't do everything I'm asked to do to help, but I've noticed a tiny little process that goes on in my mind whenever I'm asked for something. At the end of the day, I ask myself "do I know you"?
In reality I don't. In the traditional sense, we can only come to truly know a finite amount of souls in our lives. But with ambient intimacy firmly in place in modern day living, it's possible to feel like you know someone. Do they make an effort to talk to you in your Twitter stream? Have they commented on your site or Facebook page? Have you recieved an e-mail in the past with an introduction when you weren't even ambiently aware of them.
In other words, you can feel like you know someone even when you really don't. And believe it or not, sometimes this is enough to exchange a small favor, share an encouraging word or engage in a micro-interaction. Breadth should never replace depth, but sometimes you'd be surprised how meaningful it can be.