Why Is Twitter So Darn Addicting?

Now that I've rediscovered Twitter after having an account that was somewhat dormant for a while, I'm really eager to get things going. I want to engage in conversations with followers and potential followers. Without deliberate effort, I find myself getting more and more involved (and interested) in social media, marketing, etc. And more importantly, how to integrate what I'm learning to be a part of my PR efforts. These days, social media and marketing must be a part of an integrated PR approach. Enough said for now. Thoughts?