Google.com earns most of its revenue by allowing other website owners to advertise on their result pages.
This is managed through a program they call Adwords.
You can earn a share of the revenue that Google earns from AdWords by displaying these same text ads on your site.This program is called AdSense.
Every website owner should join the [...]

the Google ads you are able to display on your content pages can be either cost-per-click (CPC) or cost-per-1000-impressions (CPM) ads, while AdSense for search results pages show exclusively CPC ads. This means that advertisers pay either when users click on ads, or when the advertiser’s ad is shown on your site. You’ll receive a [...]

I’ve heard and tried the Adsense program way back 2000 at first I didn’t believe that you can really earn enough from this. As to my own experience the highest that I received from adsense is $106 in 1 month.
My goal then is to reached at least an average of $200 a month. An amount [...]