In the 21st century, an online service has the potential to garner hundreds of thousands of hits if it is social networking enabled. Now after a decade of connecting with real world friends online, people suddenly have the desire to befriend strangers.
Though not the first chat service to pair up random strangers, Chatroulette did add video zing to the otherwise bland random text chats.
Of all the web apps that have discussed above, Random Dorm is the one that could have a positive purpose.
It could connect great minds leading to awesome innovations (highly unlikely) or at the very least it could help students to hook up across campuses.
So you can pick and choose the person to have a random chat with.