I just read a good post from Josh Bernoff at Groundswell, which details the results of a study they did in the second quarter of 2008 on corporate blogging. They conclude that consumers generally don't trust corporate blogs. Here's a snippet:
"Make no mistake. This is not a plea to give up on blogging. It is a plea to be thoughtful in how and why you blog. This means that if you blog, your goal should be to create a blog about which people say “I like that – I don’t think of it as a company blog.” For the most part, that’s a hurdle you need to jump to gain their trust. I don’t mean to hide who is writing the blog. I mean it has to be more about your customers than it is about you. Blogs exclusively about companies and products are what I think generate these low trust ratings. So don’t do a blog like that. Instead, adjust your strategy based on your objectives."
Bernoff includes a graph detailing the various information sources that consumers encounter and how much they trust them. Lowest on the list, at 16%, were company blogs, whereas at the top, with 77%, was "email from people you know."