Hacker News Reader

There's also the "fad" and "uncool" factor.

When everyone's mom and dad (and their mom and dad) is also on facebook, it's going to slowly start losing it's edginess.

Then the next "cool" site will emerge.

I put more hope to the "uncoolness" factor rather than the privacy and security concerns to drive FB's demise.

I see them as the same. It may take some years for non-nerds to see the "uncoolness" of FB, but I believe they will see it, in time.