Wordpress sends pings when you add new post.  A good thing about using Wordpress is that you can edit the list of services you ping.  However, you should be careful with your ping lists depending on how often you publish. Plenty of them (pingoat, pingomatic, etc) ping multiple services. If you have 3 of them on the list and then an entry for a service that they already pinged, then you’re hitting that service 4 times with each post.

So how can you avoid this?  Answer- pick and choose the URLs you put in your ping list correctly.  (Luckily, I’ve already done the research for you)

Here’s a list of ping sites that you can add as-is. It includes the most important ones and also other smaller services. I use this list and it works wonders in terms of indexing.

http://1470.net/api/ping
http://api.feedster.com/ping
http://api.moreover.com/RPC2
http://api.moreover.com/ping
http://api.my.yahoo.com/RPC2
http://api.my.yahoo.com/rss/ping
http://bblog.com/ping.php
http://bitacoras.net/ping
http://blog.goo.ne.jp/XMLRPC
http://blogdb.jp/xmlrpc
http://blogmatcher.com/u.php
http://blogsearch.google.com/ping/RPC2
http://bulkfeeds.net/rpc
http://coreblog.org/ping/
http://mod-pubsub.org/kn_apps/blogchatt
http://www.lasermemory.com/lsrpc/
http://ping.amagle.com/
http://ping.bitacoras.com
http://ping.blo.gs/
http://ping.bloggers.jp/rpc/
http://ping.cocolog-nifty.com/xmlrpc
http://ping.blogmura.jp/rpc/
http://ping.exblog.jp/xmlrpc
http://ping.feedburner.com
http://ping.myblog.jp
http://ping.rootblog.com/rpc.php
http://ping.syndic8.com/xmlrpc.php
http://ping.weblogalot.com/rpc.php
http://ping.weblogs.se/
http://pingoat.com/goat/RPC2
http://rcs.datashed.net/RPC2/
http://rpc.blogbuzzmachine.com/RPC2
http://rpc.blogrolling.com/pinger/
http://rpc.icerocket.com:10080/
http://rpc.newsgator.com/
http://rpc.pingomatic.com
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://topicexchange.com/RPC2
http://trackback.bakeinu.jp/bakeping.php
http://www.a2b.cc/setloc/bp.a2b
http://www.bitacoles.net/ping.php
http://www.blogdigger.com/RPC2
http://www.blogoole.com/ping/
http://www.blogoon.net/ping/
http://www.blogpeople.net/servlet/weblogUpdates
http://www.blogroots.com/tb_populi.blog?id=1
http://www.blogshares.com/rpc.php
http://www.blogsnow.com/ping
http://www.blogstreet.com/xrbin/xmlrpc.cgi
http://www.mod-pubsub.org/kn_apps/blogchatter/ping.php
http://www.newsisfree.com/RPCCloud
http://www.newsisfree.com/xmlrpctest.php
http://www.popdex.com/addsite.php
http://www.snipsnap.org/RPC2
http://www.weblogues.com/RPC/
http://xmlrpc.blogg.de
http://xping.pubsub.com/ping/