20% of twitter posts relate to products and brands

(On reflection this must include all posts to or from companies on twitter, plus all the spam 'buy X now - click here to save' spam tweets, so treat this with a bit of a pinch of salt. Search for any brand name on twitter to see what I mean)
"Companies are also benefiting from Twitter, where 20 percent of the tweets contain requests for product information or responses to the requests, according to Jim Jansen, associate professor of information science and technology in the College of Information Sciences and Technology (IST) at Penn State.
"People are using tweets to express their reaction, both positive and negative, as they engage with these products and services," said Jansen. "Tweets are about as close as one can get to the customer point of purchase for products and services."
Jansen, along with IST doctoral student Mimi Zhang, undergraduate student Kate Sobel and Twitter chief scientist Abdur Chowdhury, investigated micro-communicating as an electronic word-of-mouth medium, using Twitter as the platform. Their results were published in the Journal of the American Society for Information Sciences and Technology.
The researchers examined half a million tweets during the study. The team looked for tweets mentioning a brand and why the brand was mentioned -- to inform others, express a view on the brand or something else -- and found that people were using tweets to connect with the products.
[...]
Results from the study found that users employ Twitter to inquire about product information. About 20 percent of the tweets contained product information in the form of asking and providing, thus giving companies a "rich source" of information concerning issues and questions that customers have regarding their products.
Jansen's prediction was not far off from the results, though some results did surprise him.
"A lot of the brand comments were positive," he said. "There are some good products out there, or at least products that people are happy with.""
Source: Research from College of Information Sciences and Technology (IST) at Penn State, reported by Penn State Live, 10th Septmber 2009