Yeah, I agree as well. Facebook has made a pretty big impact in the way people stay in touch with one another.
Though I'm not quite sure why it was that Facebook succeeded while Myspace (which had been around for years) just kinda foundered. Does anyone use Myspace anymore?
I'd attribute it to two reasons, one because of Myspace and one because of Facebook.
First, Myspace allowed (and encouraged) aliases, whereas Facebook requires real names in profiles. It's tough to find your friends or your friends to find you when profiles are made up of users like "Sugar_Lady21" and "GymDude411."
Second, Facebook's rollout was gradual - it started college only (college by college), then companies, then high school, then anyone. It created envy among those who were not in the "cool group" of Facebook users, and the ones who were allowed viewed it as an exclusive club. When they were allowed to sign up, they were met with an already-large network of people to interact with. It was a brilliant growth strategy (even if unintended - it was originally meant to manage the growth and their available resources). People soon forgot they even had Myspace profiles.
Facebook became MySpace for adults.