AdSense earnings tend to come from AdSense for content, this is the reason why they made the main focus of effort optimizing AdSense for content as do the blend color, placement and ad size. But I think it's time we also pay attention to the AdSense for search, a small search box that adds functionality and monetization of our site.
Here are some Tips To Increase Earning Adsense for Search:
Customizing the display
You can always use the default settings, but it will work much better if you change the colors to customize the background and text. The search box should look like the page, blends well with other sites but quickly recognizable by the user. If you know a little HTML, you can even try playing with the configuration of various elements.
Select to open the search results on your own site
When configuring the AdSense search box by asking you whether you want the search results on Google or on your own web site. It is better to choose the latter because it makes the users on your site, and you have greater control over the design. Moreover, this is not a bad idea to put a search box on the results page itself, for users who might want to create a new search.
Optimize page ad placement results
You can choose between three configurations. where the placement of advertisements in the pages of results, but Google recommends selecting "Up and Right" because it has the best results in tests.
Use the targeting options
One of the new things about AdSense for Search is that you can improve the results to make them more relevant to the audience. For example, if you run a site about Nokia, you can enter the keyword "phone", "Nokia" and "3G" so that the results and will likely relevant ads that Nokia phones with 3G capabilities.
The search box to maximize visibility
AdSense search box should be placed where you can find it at a glance. Locations such as the navigation left or right column and below the header is a good place for this. It's important to place it above the fold, which means the reader does not have to scroll down the page just to see it. To avoid confusion, the search box should be placed evenly on all pages. This should not be a problem if you use a CMS like WordPress and Joomla templates.