AdSense

Google's "contextual advertising" network. Publishers large and small may automatically publish relevant advertisements near their content and share the profits from those ad clicks with Google.

AdSense offers a highly scalable automated ad revenue stream which will help some publishers establish a baseline for the value of their ad inventory. In many cases AdSense will be underpriced, but that is the trade off for automating ad sales.

AdSense ad auction formats include

• "cost per click" - advertisers are only charged when ads are clicked on
• "CPM" - advertisers are charged a certain amount per ad impression. Advertisers can target sites based on keyword, category, or demographic information.

AdSense ad formats include

• text
• graphic
• animated graphics
• videos

In some cases I have seen ads which got a 2 or 3% click through rate ("CTR"), while sites that are optimized for maximum CTR (through aggressive ad integration) can obtain as high as a 50 or 60% CTR depending on

• how niche their site is
• how commercially oriented their site is
• the relevancy and depth of advertisers in their vertical

It is also worth pointing out that if you are too aggressive in monetizing your site before it has built up adequate authority your site may never gain enough authority to become highly profitable.

Depending on your vertical your most efficient monetization model may be any of the following

• AdSense
• affiliate marketing
• direct ad sales
• selling your own products and services
• a mixture of the above

See also:

• Google AdSense program - sign up as an ad publisher
• Google AdSense heat map - shows ad clickthrough rate estimates based on ad positioning.
• Google AdWords - buy ads on Google search and / or contextually relevant web pages.