I'm sure the number of marketing-related messages on Twitter hasn't escaped you. As I've noted before, Twitter is like a marketer's big "easy button" for the Internet, except when you push it, you get another marketer. So, you might be surprised by the findings of this study, which claims that over 90% of tweets are by "real people," while "only" about 8% are from marketers. The conclusion: marketers need to amplify and syndicate their messages. I've written previously about the power of small numbers, and here is yet another deceptive example. I know 8% seems like a small number, but honestly: do you think nearly one-in-ten Americans is a marketer? Maybe by some extraordinarily liberal definition, yes, but at the very least, I'd say marketers are doing just fine.
Anyway, if you are looking for quantity, buy TV or Radio. Here's to keeping that 8% right where it is :)