The question of whether or not AdSense is a secure way to make a living comes up every now and then. A new WebmasterWorld thread named Is AdSense a valid business model for publishers? goes right into that, and its three pages long already.
I know of a few people who have decided that their blog was bringing in enough monthly income. So they decided to move to a low cost area and continue their blog. I do not know if AdSense alone sustains their livelihood, but I do know they also have normal banner ads on their site.
The forum folks tend to believe AdSense is a viable and even sustainable source of income. But like any business model, there is always some risk.
Forum discussion at WebmasterWorld.

Comments:
Chris Beasley
11/24/2005 04:36 am
I would say that relying on any single income source is a bad idea.
Cameron Olthuis
11/26/2005 06:30 pm
^^ Including a job??
Kevin Kennedy-Spaien
11/27/2005 02:16 pm
I would say, Yes, that includes a job. How many people do you know who've managed to keep one job throughout a career? If you lost your job, wouldn't you be happy to know you had other sources of income?
Johnny
11/28/2005 10:35 am
We should not depend only on google adsense for income source, we should search for other resourses of income. here is my weblod:<a href="http://blog-magic.blogspot.com">Make money blogging online</a>