This is an excerpt from a darn interesting article in the Christian Science Monitor of 29 March, 2006, entitled Google's Hidden Payroll.

Jayant Kumar Gandhi, a former software engineer in New Delhi, is one of hundreds of thousands around the world on Google's shadow payroll.

In his spare time, Mr. Gandhi runs a free computer help website and recently began running ads by Google on his homepage as part of Google Adsense, a program that pays website publishers for advertising space. When visitors click on the ads on Gandhi's site, Google makes a small profit from the advertiser, and in turn, pays a percentage of that profit to Gandhi.

Such clicks can translate into pennies - or dollars - a day for a Web publisher. "I had no intentions of using it for more than a week," Gandhi says. "I didn't believe the stories that Adsense paid decent money. I ignored them as a marketing gimmick."

But Gandhi's Adsense profits have exceeded his wildest dreams. He now earns about $1,000 a month from the program, the same salary he previously earned as a software engineer. His new income has allowed him to leave his job and return to school. "Today I am able to sponsor my higher studies because of Adsense," he says.

The article continues...

It is easy to join. A Web publisher or blogger simply completes an online Adsense form. Google then places ads on the site, similar to those that appear next to search results on Google. The ads are contextually matched to content on the host site, so a blog post about having a headache might attract ads for pain-relief medicine.

Anyone with a site is eligible, and Web forums are awash in success stories of small online entrepreneurs placing ads on their sites, sitting back, and watching checks from Google roll in.

I encourage you to pop over to the CSM site and read the entire story, it's quite inspiring, actually: Google's Hidden Payroll.

Also, if you haven't yet signed up for Google AdSense, please do consider it: Getting started with Google AdSense