TWEETLISTER? IS IT FOR THE BIRDS?

I got this header as part of an email today. Twitter wants to help me post listings using Tweetlister. I did not look to closely at it because I am always curios what other rainers are using and so I ask "What do you think of it". I have been tweeting for a while and have posted new listings and open house, but for free.

Any users out there? What are you paying? ROI?