Social Networking Sites

Facebook
- Real time status updates
- A lot going on at once
- Real time chat option available
- High user population
- News feed is tailored to the user
- Home page is the central hub 
Twitter
- Real time status updates
- Usage of hashtags
- Hashtag trends show what Twitter users are talking about
- No private real-time chat option, private messages only
Pinterest
- Home page is tailored to the user
- Home page feels a bit overwhelming, since multiple pins go across the web page and vertical as well
- Peaks creative users' interest 
- Private message option only 
Tumblr
- Home page is tailored to the user
- Private message option only 

Overall, all four social networking sites have their home pages tailored to the user. Personalization is what defines a person's profile, and central hub (home page). Pinterest and Tumblr appeal to creative minds.