Back in the day there were only a few ways to communicate on the internet, and if you weren't on the same ones, then you just didn't talk. AOL's messenger, known as AIM, was the biggest one. I remember countless hours talking with friends and adult men I had no business talking to. It was the wild west of the internet, and we were all just figuring it out. It wasn't always pretty, it wasn't always safe, but it was what we had.
The AIM profile was your way to talk about yourself and give people a taste of your personality. If you knew HTML you could make an elaborate profile. It was also a great way to be passive aggressive. If a friend pissed you off you could reference it in your profile, or if you liked a girl you could say something like, "I have a crush. I wish she would just message me."