That's a great example of a post where the user pre-pends \tweet\ to the post, to get it to tweet to twitter, but a filter sees the string "buy" or "sell" multiple times, and refuses to tweet it. So it's all about filtering out tweets that one would not want tweeted, and that takes some development and some judicious coding that is acceptable to those who are considering the use of the service, to tweet some post made in trollbox with some degree of automation.