If Google have approved your Adsense application, it's time for you to create and add Adsense for search button on your blog pages. What this means is that your users can search the web on Google right from your blog.

Adsense for search offers the following advantages:

Earn revenue: When your users search google through your blog, you will earn revenue when they click on the relevant ads on the search results.
Helps your users find contents across the internet without leaving your blog thereby decreasing bounce rate.

With Adsense for search, you are offered two options to show search results.

Show search results within the blog page.
show search results on Google page.

On this post, we are going to look at how to show search results on blog page, this is more advisable as it helps you to keep your readers longer on your blog thereby decreasing your blog's bounce rate.
How to create Adsense for search engine on your blog:
Login into your Adsense account, click on "my ads", click on "search" on the left, click on "custom search engine" and then select "new custom search engine".



On the next page, put your name, keywords and other data.



Scroll down to "search box style". Here choose the style you like, i prefer the default. On the "text box length", chose the your prefered search box. Mine is 40 characters.



Scroll down to search results, choose "on my website using iframe" this displays search results on your blog page instead of google page.



On the "URL where search results will be displayed" box, put yoursite.com/search

Now click on "save and get code", on the next page you will see two separate Adsense codes.

Head to your wordpress dashboard and create a new page with search as the name. This is the page where all search results will be shown. Make sure that you use no index for this page.

Open the HTML editor on the page you just created, go and copy the 2nd Adsense code and paste it on the page. Click on publish.



Go to appearance on your wordpress dashboard, click on widget, create a text widget and paste the first Adsense code on it and save.



you are done. You will soon start earning from search results.

If this post helped you please share.

Good luck.

http://onlineprenuer.com/customise-adsense-for-search-box-add-blog-page/