A great example from Stephen O'Grady on how he checked blogs for opinions on products/services he was thinking about purchasing. His decision to purchase/not-purchase was based upon input from other bloggers.

Example 1: Apple PowerBook - Young Pup's PowerBook woes

Example 2: Vonage - Poor reviews from Christopher and Ev

More and more people are doing this. Corporations might not want to take notice since they might think we are a minority, but people like Stephen and I are the alpha-geeks to our family and friends. When a friend wants computer/cellphone/camera/etc guess who they ask?