WordPress Hacks : 1 Display AdSense Ads to Search Engines Visitors Only

In this serie of articles, we’ll show you 10 new useful WordPress hacks to unleash the power of your favorite blogging engine. Each hack has an accompanying explanation, so you’ll not only unleash the power of WordPress but also understand how it works.

For this first post, i choosed to write about adsense in wordpress, and how to show adsens search only for visitors who come from Search Engines.

The problem. It’s a known fact that regular visitors don’t click on ads. Those who do click on ads are, 90% of the time, visitors coming from search engines.

Another problem is Google’s “smart pricing.” Being smart priced means that your click-through rate (CTR) is low and the money you earn per click is divided by between 2 and 10. For example, if a click would normally earn you $1.00, with smart pricing it could earn you as little as $0.10. Painful, isn’t it? Happily, this solution displays your AdSense ads to search engine visitors only, which means more clicks and a higher CTR.

The solution.

1. Open the functions.php file in your theme.
2. Paste the following code in it:

   function scratch99_fromasearchengine(){
     $ref = $_SERVER['HTTP_REFERER'];
     $SE = array('/search?', 'images.google.', 'web.info.com', 'search.', 'del.icio.us/search', 'soso.com', '/search/', '.yahoo.');
     foreach ($SE as $source) {
       if (strpos($ref,$source)!==false) return true;
     }
     return false;
   }

3. Once done, paste the following code anywhere in your template where you want your AdSense ads to appear. They’ll be displayed only to visitors coming from search engine results:

   if (function_exists('scratch99_fromasearchengine')) {
     if (scratch99_fromasearchengine()) {
       INSERT YOUR CODE HERE
     }
   }

   Code explanation. This hack starts with the creation of a function called scratch99_fromasearchengine(). This function contains a $SE array variable in which you can specify search engines. You can easily add new search engines by adding new elements to the array.

   The scratch99_fromasearchengine() then returns true if the visitor comes from one of the search engines containing the $SE array variable.