Pay to read a blog? Vin Crosbie entertains the thought with commentary from Rick Bruner.
I don't know -- to me blogs aren't content, but pieces of conversations. The more involved in those conversations a blog is, the more valuable the blog. If you pay for access to blogs, you limit the number of participants who can enter the conversation, thus making them less valuable.
Business Blogs are really a new form of marketing or PR. They are a way to engage with a customer base to grow a customer base and keep that customer base engaged with your business.
For the most part, the business blog isn't a business ends, but a means to more business.