I have no faith in Twitter's business model at all. I've come to that conclusion by having a Twitter account and using it every day. Like many users I'm there purely for the "lulz" and only follow funny people. I rarely tweet myself. The most annoying thing is the almost daily emails from Twitter with subjects like "charge ahead with these 3 campaigns" trying to get me to become one of their paying customers.
I find it hard to believe that advertising through Twitter helps businesses at all.