I agree with Katie, like any other social network, it takes time to build a following and credibility. The one thing that I really like about Twitter is that it is really easy to build relationships with non-artists, therefore tapping into a whole other market of buyers! I've been using it for over a year and I am happy with the cross promotions and followers that I have been able to gather one by one (that's my own philosophy...relational, no spam). Start with connecting with some friends who are willing to retweet your tweets and go from there! Best of luck! Aloha, Connie