I don’t suffer from that problem: the second someone retweets promotional crap they are gone. Once in a blue moon someone like Tim O’Reilly or James Gleick does that but it’s not enough to make me very upset. Considering 1/3 of all television is now ads and most of them are repeated hundreds of times, for things like adult diapers and mesothelioma settlements (ad/commercial free makes a lot of sense). Blanket statements like ‘Twitter is a time waster’ are pretty close to ‘Java is a bad language because some people write crap code with it.’ It is kind of funny that instead of giving OP a few simple suggestions so many people have told them how much more enlightened they are.. there’s a good section in Sapiens about that.. 🙂 if you don’t like Twitter, by all means don’t use it..