Blog for business? Why not. Someone has own small business need advertising online for get new customer to buy something their business. Want to make some new website but have' not some budget to developt it. Why not using free dinamic website like blog to solving this problem?
Blog so easy to developt and maintaining content with dinamic dashboard. We can make update every day news about my own business.

And another person developt their blog can monetize using third advertising, afiliate can get profit share using blog. In this day blog so easy customise using new template and powerfull widget any attracting loyal visitor their blog. So u have any blog to monetize right now? if your answer is not, why not act now :)

You can start using http://blogger.com or http://wordpress.com,

good luck