Blogger Blogs

Where do blogs come from, anyway?

Sometimes, I hit the "next blog" button at the top of the webpage, just to see what else is out there. I have a couple of questions about those blogs....

First, how does Blogger determine which blog is "next"?

Second, why is there so much blogging going on?

And third, what's the deal with all the blogs that are just advertisements? Are these people/companies using blogs because it's easier than setting up a website? Is it meant to inspire conversation about their products? Some of these blogs look like a series of the same blogpost over and over, and all of them are just an advertisement for the product.