Ping services are tools you can use to let other people know you’ve updated your blog. WordPress automatically notifies popular Update Services that you’ve updated your blog by sending a XML-RPC (http://www.xmlrpc.com/) ping each time you create or update a post. Ping will notify website Technorati or DayPop that your blog has been update. WordPress in default setting will only have one ping services, Ping-o-Matic. To notify more website you need more ping services. To add more ping service in WordPress follow this step :
1. Login to your Admin Panel.
2. Go to Options>Writing.
3. Go to Update Services, copy XML-RPC Ping Services list.
4. Paste XML-RPC Ping Services list in your Update Services List.
5. Now Update your setting.
Now, everytime you posting new post, WordPress will notify many website and bring more visitor to your site.