What makes a blog successful and worthwhile

From the following article:

"Blogging is a time consuming activity, and people eventually get tired of investing in an activity which yields no returns. A good return on the time invested in maintaining a blog is the critical factor ensuring the continued survival of a blog. Blogs which produce monetary returns for their maintainers not only motivate bloggers to keep going, but also let them invest more time and resources in producing content."

Now, for me this really doesn't seem to be the case. The websites I go to, in the main part, I don't go looking to spend money. The only ones would be amazon.com or to pay bills online. Mostly I read blogs for entertainment and to have a look into the lives of people all around the world. For me blogging is about being part of a community, not looking for a way to make a buck!