You can only earn a very small pocket money via Adsense. As a blogger with 160+ posts, I can tell you that it is worth the effort as you can promote your books, products, and services via it. It is a great learning and networking tool as well.
Lalit Mehra wrote:What if I start a website of my own. Will it be worth it ?
If you are only measuring money earned on the site, probably not. The biggest benefits from blogging are learning and name recognition. Which turn into opportunities or the platform Arulk mentions.