It's basically the only way I maintain online relationship with most of my non-technical friends. Most of them just use email and FB. If your only circle is tech savvy folks, then FB's value is probably not very high.
There's something sort of sad about this statement. Actually, now that I think about it, it was less sad when the site was feed-based. Important stuff bubbled to the top and I felt connected. Now that it's stream-based, it's just a flood of minutiae and the important stuff gets lost in the noise. My FB-connected relationships feel less weighty as a result. Weird!