You would almost think blogging was dead, the way headlines are dominated by Twitter, Facebook, and social media in general. I've always considered blogging to be a part of social media anyway, as the commenting factor lends to engagement between author and user.
There is no stronger force in marketing than word of mouth. A salesperson, or evangelist, as they like to be called nowadays, has no leverage or influence greater than the authentic voice of a friend, or the experienced voice of a fellow consumer.
If a company wants to try out word-of-mouth marketing, they need to understand that building buzz without disclosing who's paying for that marketing could cause them a Federal-sized headache.