WordPress has a great feature called Update Services that can help you ping blog directories, social media sites and search engines when your blog has new updates. This feature is very helpful but some bloggers don’t pay much attention to it.
“WordPress automatically notifies popular Update Services that you’ve updated your blog by sending a XML-RPC ping each time you create or update a post. In turn, Update Services process the ping and updates their proprietary indices with your update. Now people browsing sites like Technorati or Sphere can find your most recent posts!” (http://codex.wordpress.org/Update_Services)
Using this feature, you don’t have to submit your RSS manually, everything is done automatically when you create or update a post. By default, WordPress adds the update service provided by Ping-O-Matic to your blog. Ping-o-Matic is a very reliable service, just one “ping” from you, it will let many other services know that you’ve updated your blog.
Ping-O-Matic works fine. However because the number of social media services are growing day by day, you should add more services to our WordPress ping list. You can access your ping list in WordPress via Settings -> Writing -> Update Services. The following is the list of services I am currently using for my blog. If you have others, please share them with us.