Adsense has introduced a new feature in Adsense for search. Now it is powered by Custom Search so you have more control of what users search and where the search results are displayed from. Also, it has relevant ads to the right of the search results that are related to the search term, bringing you more revenue. You also have more control over keywords, making the search results even more relevant.

Here are some of the new features:

• Site Search: You’ve worked hard to attract users to your site, so it’s understandable that you’d be concerned about those users leaving through web search. Now you can choose to provide just site search so users can find all the information they’re looking for on your site, and you can host the search results on your own pages so that they can find that information without leaving your site.
• Improved indexing of your pages: We’ve recently improved our indexing technology so that you can provide a more enhanced Site Search experience for your users. AdSense for search will now index even more pages of your site, as long as we’re able to crawl them, so that your users will see more results from your site in your AdSense for search results. Stay tuned for more updates on future crawl and indexing improvements!
• Vertical search: You can also allow your users to search across multiple sites - this could be a network of sites that you own or other related sites that you think your users might find useful. If you write book reviews on your blog, for example, you can use vertical search to specify a list of online bookstores for users to search through. Other examples of vertical searches include computer forums, travel blogs, political sites you endorse, etc.
• Tuning search results and ads with keywords: Search terms can have different meanings in different contexts, so you can now configure your search engine with relevant keywords. Let’s say you manage a site about yoga - you can enter keywords such as ‘yoga,’ ‘exercise,’ and ‘meditation’ so that when a user searches for ‘mat,’ the search results and ads will be more related to yoga mats and less to commercial floor mats. (You can see an example of this in the video below). In experiments, we’ve found that this tuning has led to an increase in earnings for publishers.
• Selecting ad location: Do you want ads to appear at the top and bottom of your search results? Or along the right sidebar as well, just like on Google.com? Now you can make the call on where ads are placed. (Here’s a tip: we’ve found that placing ads at the top and right monetizes the best for publishers.)
• Quick and easy updates: Just as you use our ad management feature to quickly change the settings for your ad and referral units, you’ll be able to do the same for your search engine within your AdSense account. Your settings will be saved in your account, so you won’t need to generate new search code for each change.

Don’t forget to go to Google Adsense Blog for more information and a cool video that explains everything in a more user friendly way