Permanence, meaning everything a user does, says or posts on Facebook is recorded and never erased. Facebook is like a digital journal of your life. Memories and photos will greet you every time you log in.

Identity is also a big part of Facebook. Mark Zuckerberg realized ten years ago that by tying individuals to their school email addresses, you could bring offline relationships online. Facebook is now like a passport to the Internet, giving people credibility whenever they sign on to a partnering website or comment on a friend's post.

Startups that have decided to take the opposite approach and focus on ephemerality and anonymity have excelled. Snapchat promises users that nothing they send on its network will be saved or come back to haunt them later. Whisper and Rumr are apps that allow users to post secrets anonymously. Whisper is producing about 3 billion pageviews per month.