This link from the Pear Analytics blog points to a white paper summarizing use of Twitter. The largest category of Tweets was described as – Pointless Babble (41%). Pass-along value (I hope this post would have pass along value in that it provides a resource for your consideration) represented only 9%.
Reminds me of a joke – punchline – there must be a pony in here somewhere (alright except for this final bit of pointless babble, you have to admit this comment had some pass along value).