Facebook is so popular because of the the people that join Facebook. People join Facebook because it is easy to chat and message people around the world. Facebook can be addicting because there are many 'applications' that can be added to your profile that include games and quizzes. You can communicate with people who live halfway across the world. Also, it is free.
They are both very popular. Facebook more so than Twitter.
Facebook is so popular with teenagers because they can interact with other people and there friends, but they can also block their parents off of there facebook profile so that the parents don't see any inappropriate their doing.
FACEBOOK!
I've never heard of Facebook so it's probably not very popular
no YouTube is not the most popular website google more popular so is Twiter and facebook
Because it is the social networking site.
Facebook became popular in 2004
Both are very Popular. But Worldwide Facebook is Defiantly more Popular!
facebook is better
Facebook for sure!