- Comments are focused. On Facebook, dozens of people can comment on, and argue over, any idea you share. On Twitter, comments are directed back to the original poster, and maybe a select few. Your comments occur in your own posting, and are a part of your tweeting record for all to see.
- The Re-Tweet. The primary mode of engagement on Twitter is the re-tweet (RT); re-tweeting encourages thoughtful, positive messages. People obviously RT items they agree with, so positive messages are more likely to spread.
- One-Way following. Twitter allows anyone to follow anyone. I don't expect the people I follow to necessarily follow me, and I don't necessarily follow those who do follow me. This one-way street allows people to fine-tune their stream of information so that they don't see information they don't want to. In fact, I often unfollow and re-follow people later, when they share a political view too often that I find unpalatable.
- Twitter seems more fact-oriented. In my observation, Twitter users tend to post links to articles to share a point more often than Facebook users. Additionally, the public, searchable nature of the site means that people who are stuck in rhetoric without any fact basis, tend to be ignored.
- Twitter isn't about self-congratulations. Again, maybe more my experience than true fact, but the lack of a "Like" option on Twitter encourages people to post things they want to say, without an attempt to have others congratulate them for saying it. Similarly, the simplicity of the site tends to negate vague or passive-aggressive posts. Sure, a user can posts an open-ended plea for attention, but it will likely get lost in the noise.
Don't get me wrong, I still use Facebook for certain things, but it is awful for politics and sharing thought-provoking ideas. Bring on the family pictures though!