Indeed, and I recall there being only rudimentary profiles and I'm not even sure there was messaging functionality. You had to actively visit people's profiles

Indeed, and I recall there being only rudimentary profiles and I'm not even sure there was messaging functionality. You had to actively visit people's profiles to see what they were up to and had to follow conversations from wall to wall. We all signed up but we jokingly referred to it as Stalkerbook. In other words, it was nothing like it is today, where it has become a replacement for a bunch of existing things (e.g maintaing address books) and allowed a slew of new things (light touch contact, wider networks and news feeds).