Definitely some good information here. The only thing I would be really concerned about is the idea of using Twitter in that matter. Twitter was developed for people to keep in touch with the smaller and simpler things that happen in people's lives. I'm afraid that if you use it to blatantly market properties, the people who are following you will be less likely to keep themselves updated with what is going on in your lives.

How about this for an alternative: instead of just saying something like "Just listed! 3 bedroom house in x part of town. Brand new kitchen and bathrooms! This will be gone quick. Want to see it? Call now - 555-1212", maybe phrase it in a more personal manner like "Checking out this new 3 bedroom house in x part of town. Heard it looks amazing!". That way, it sounds more personal and goes along the lines of what Twitter is designed to work.

Then again, if you just have a ton of buyer agents that are following you, your Twitter message would probably work great. I'm just thinking of all the other non-buyer agents that may be interested in following you...