Blogs come in many varieties, I'm currently reading Rebecca Blood's book on it, titled 'Practical Advice on Creating and Maintaining your Blog: The Weblog Handbook'
I'm of the opinion that many online writings can be viewed as blogs, depending on how lax your criteria is.
Again, know your source, and analyse the author(s) of what you read. Don't get taken by a wolf in sheep's clothing.
I wonder if people consider this site to be a blog...
The blog revolution? Or the recurring expression of naivety?
Internet marketing gets a boost with faux blogs and the google link popularity algorithms.