How important is face-to-face friendship?

An article in The Atlantic this month discusses the counterintuitive notion that Facebook might be making us lonelier.  Much has already been said about this, but one thing caught my eye about it:  the idea that face-to-face communication is the only kind that counts.  Err, OK.

John Cacioppo, author of the book Loneliness, asserts that communication on the Internet allows only surrogate intimacy, which cannot make up for the absence of a face-to-face confidante.  Now, I haven't read his book, so I'm receiving his argument secondhand (he didn't write the article), and it may be more nuanced than that.  And to be fair, we're talking about the closest kind of friendships, those where you can discuss anything.  Still, the absolute nature of the argument bothers me - that Facebook is good for you when you use it to arrange to meet friends, bad for you when you use it to avoid meeting friends, and otherwise neither good nor bad.  I've written plenty about the importance of getting out and meeting face-to-face (see links within this post), but I find this a little over the top.

Cacioppo's implication is that there is no value in exchanging ideas with other people via a keyboard.  I've phrased it that way deliberately:  communication is exchanging ideas.  (Sure, if you meet face to face you can also exchange bodily fluids, but that's a whole different question.)  History has given us an ever-expanding list of options for communication:
  1. In person
  2. Writing a letter
  3. Telephone
  4. Internet chat or real-time text messaging
  5. Videoconferencing
In person, you can communicate via the literal English meaning of your words, via the tone, timing, and emphasis of your words, and by gesture and posture and touch.  The other modes of communication rule out one or more of those kinds of information.  The only thing that can only be done in person is touch.  Does that mean it's impossible to maintain an intimate friendship via videoconferencing?  How much meaning do we normally convey to our closest friends through touching them?  I'm not convinced it's all that much.  I'm willing to believe it's important, but is it irreplaceable? 

I think we can all agree that a balanced life is a better one.  I've argued many times that getting out and meeting people face to face is important.  But let's not discount what can be conveyed with pen and paper.  Otherwise a whole lot of English majors might get irate.