There are a variety of blogs out there serving various agenda. Here's the Wikipedia definition.
"A blog (a contraction of the term weblog) is a type of website, usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in reverse-chronological order. "Blog" can also be used as a verb, meaning to maintain or add content to a blog."
At last count there were in excess of 112 million blogs. Some are extremely useful with daily facts, statistics and useful information to the reader. Others can be just self serving, like a recording artist stating when the bands new album comes out and where you can see them etc.
With the internet, fact is not always verified because anyone with a keyboard and an internet connection can post material. Currently there are also sites that thrive and survive strictly on posting "gossip", like Gawker.
Video on Youtube
As the internet continues to evolve, more debate will be raised on what can be said, how it's handled, and who is ultimately liable for what is being said.