Earn money online without spending any money

Many people know the easiest way to make money online but few know how to make the best use of it!

Earn money online without spending any money

1. Create a Free Blog in Blogger.com .
2. Earn money by configuring Google AdSense for your blog

I have already published my personal experience with blogging.  But still I am wondering why some people not using this opportunity to earn money as a part-time job or a full-time blogger?