Update 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 ping each time you create or update a post. In turn, Update Services process the ping and updates their proprietary indices with your update.
Most people use Ping-o-Matic which, with just one “ping” from you, will let many other services know that you’ve updated. As for why, Ping-O-Matic puts it best:
So why would you want to be on these sites? One word: traffic. Blogrolling scripts like WordPress check update services to see if you’ve updated and then shows it on everyone’s site — usually by moving you to the top of people’s blogrolling list or putting a recently updated indicator by your link. Services spider your links to track who links to you and who you link to; almost in real time. If you show up on someone’s link list, they’re likely to visit your site to see what you said, increasing your exposure. Sites like weblogs.com and blo.gs list recently updated blogs. Lots of people browse these when they’re bored. Many of the services offer their own forms for pinging their own service, but keeping track of all those services is a hassle.
If you do not want the update services to be pinged, remove all the update service URIs listed under “Update Services” on the Settings->Writing administration screen of your WordPress installation.
Certain web hosts – particularly free ones – disable the PHP functions used to alert update services. If your web host prevents pings, you should stop WordPress from attempting to ping.
XML-RPC Ping Services
http://rpc.pingomatic.com http://rpc.twingly.com http://www.blogdigger.com/RPC2 http://ping.blo.gs/ http://ping.feedburner.com http://rpc.weblogs.com/RPC2 http://www.pingmyblog.com
- An alternative is Feed Shark, which pings over 60 services for free.
WordPress Multisite Network
By default, editing the Ping Services for a WordPress Multisite network site is disabled. This can be re-enabled with a plugin such as the Activate Update Services plugin.