There are 2 type of contextual advertisement units that you can put in your site - ad units and link units. Ad units displayed the ads directly on your site. An example is the Wide Skyscraper Ad unit you see in the left sidebar in this blog. You will be paid as explained as above. An example of link unit is the one you see just below the title of this blog in the Header. You will not be paid for clicks on links in link units. However, clicking on one of them will cause a page with ads relevant to the title of the link. You will be paid as explained above for clicks or impressions as explained above. The maximum number of Ad units you can put in a page is 3, and the maximum number of link unit is 1.
UPDATE 2 February 2007: The pricing structure for AdSense and AdWord have been improved and it is now easier to get a referral fee for them. If within 180 days, the person you referred to AdSense earn their USD5, your account will also be credited with USD5. If within the same period, they earned USD100, your account will be credited with an additional USD250. In addition to these, if within any 180 days you referred 25 publishers who each earn more than $100 within 180 days of their respective sign-ups and are all eligible for payout, you will be awarded a $2,000 bonus (bonus payouts are limited to 1 per year).
AdSense Search
You can put up to 2 AdSense search boxes on your site. They can be just for searching the Web, or they can be used for searching only the content of your site. You will not be paid for readers for using the searchbox, only if they click on any ads that may be displayed in the search result page.Referrals
You can also earn by referring people to join AdSense or AdWord, or to get other things like FireFox with Google toolbar, Google Pack, Picasa. You can see examples of referral text links at the top of the right sidebar of this blog. You can place a maximum of 2 referral buttons or text links per product on your sites, and if your readers click on these, you may be paid under certain conditions. Currently, there are 4 referral products that available - Google AdSense, Google AdWords, FireFox with Google toolbar and Picasa (now being replaced by Google Pack, depending on which country you reside in). For Google AdSense, if your reader join AdSense via your referral button, you will be paid US100 if they manage to earn US$100 within 180 days (6 months). For Google AdWords, if your reader sign up and spend US$100 within 90 days, you will earn US$20. For FireFox with Google toolbar, if your reader download, install and runs the browser for the first time, you will be paid up to US$1 depending on their geographical location. For Picasa, when a user you've referred to Picasa downloads and runs the product for the first time, you will earn up to US$1, also depending which geographical location.UPDATE 2 February 2007: The pricing structure for AdSense and AdWord have been improved and it is now easier to get a referral fee for them. If within 180 days, the person you referred to AdSense earn their USD5, your account will also be credited with USD5. If within the same period, they earned USD100, your account will be credited with an additional USD250. In addition to these, if within any 180 days you referred 25 publishers who each earn more than $100 within 180 days of their respective sign-ups and are all eligible for payout, you will be awarded a $2,000 bonus (bonus payouts are limited to 1 per year).
