From Ads.
the annual revenue of the google website is 300 million per year
Google's revenue comes from it's Paid Search and Banner Advertising services. These services accounted for about 97% of Google's revenue in 2008 according to their 2008 Financial Statements. Read more on their Investor Relations Blog: http://investor.google.com/releases/2008Q4_google_earnings.html
The sale of advertisements.
Google Adsense is a program that involves gaining revenue from people watching the users online content. After an account is created on Youtube and other locations, ads are added to the site, and revenue is accrued that way. Having good, popular content is the best way to gain revenue.
6 billion a year
To find information about Google revenue, one can visit the Google website. Other websites that offer this information are: Wikipedia, PC World, The Motley Fool and Press Gazette.
By selling the software it creates and commisions that advertisers pay to keep their advertisements on Google (and that is why there are sponsored links).
Adwords is used to target advertising for various company's products. Companies write up "ads" using "keywords" that target certain demographics. When users click on those ads, google charges a percentage for every click- thereby bringing in revenue.
Google "List of largest companies by revenue."
The sale of advertisements
revenue is what pays the expenses of running the business and hopefully you can even make enough revenue above expenses to make a profit
Google share 68% of the adsense revenues with the publisher.