Update services are used by search engines to keep their directories up to date. By telling WordPress which update services it should be talking to—often referred to as “pinging”—you’ll ensure that search engines are aware of updates to your blog the instant they happen—or perhaps with a few millisecond delay.
You’ll find this under Writing in the Settings menu in the back-end of WordPress. Once there, you’ll notice this service is already in the Update Services box:
http://rpc.pingomatic.com/
You can leave pingomatic in place, but you should add my full list of services, listed below.
UPDATE: Since I first published this post in February, I’ve updated my master list of update services—some of which are unverified. But, there’s no harm in using them, so you have nothing to lose. Drop these into the Update Services box and watch your traffic double:
http://rpc.pingomatic.com/
http://api.moreover.com/ping
http://api.my.yahoo.com/rss/ping
http://blogsearch.google.com/ping/RPC2
http://cullect.com/feed/ping
http://ping.bitacoras.com
http://ping.feedburner.com
http://ping.syndic8.com/xmlrpc.php
http://rpc.blogrolling.com/pinger/
http://rpc.icerocket.com:10080/
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://topicexchange.com/RPC2
http://www.blogdigger.com/RPC2
http://www.blogoole.com/ping/
http://www.popdex.com/addsite.php
http://www.wasalive.com/ping/
http://www.weblogues.com/RPC/
http://blogping.unidatum.com/RPC2/
http://1470.net/api/ping
http://api.feedster.com/ping
http://api.feedster.com/ping.php
http://api.moreover.com/RPC2
http://api.my.yahoo.com/RPC2
http://bblog.com/ping.php
http://bitacoras.net/ping
http://blogdb.jp/xmlrpc
http://blog.goo.ne.jp/XMLRPC
http://blogmatcher.com/u.php
http://bulkfeeds.net/rpc
http://coreblog.org/ping/
http://mod-pubsub.org/kn_apps/blogchatt
https://phobos.apple.com/WebObjects/MZFinance.woa/wa/pingPodcast
http://ping.amagle.com/
http://ping.bloggers.jp/rpc/
http://ping.blogmura.jp/rpc/
http://ping.blo.gs/
http://ping.cocolog-nifty.com/xmlrpc
http://pinger.blogflux.com/rpc/
http://ping.exblog.jp/xmlrpc
http://ping.myblog.jp
http://pingoat.com/goat/RPC2
http://pingqueue.com/rpc/
http://ping.blogg.de/
http://ping.rootblog.com/rpc.php
http://ping.weblogalot.com/rpc.php
http://ping.weblogs.se/
http://rcs.datashed.net/RPC2/
http://rpc.blogbuzzmachine.com/RPC2
http://rpc.britblog.com/
http://rpc.newsgator.com/
http://rpc.tailrank.com/feedburner/RPC2
http://rpc.wpkeys.com/
http://services.newsgator.com/ngws/xmlrpcping.aspx
http://signup.alerts.msn.com/alerts-PREP/submitPingExtended.doz
http://trackback.bakeinu.jp/bakeping.php
http://www.a2b.cc/setloc/bp.a2b
http://www.bitacoles.net/ping.php
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.lasermemory.com/lsrpc/
http://www.imblogs.net/ping/
http://www.mod-pubsub.org/kn_apps/blogchatter/ping.php
http://www.newsisfree.com/RPCCloud
http://www.newsisfree.com/xmlrpctest.php
http://www.rssfwd.com/xmlrpc/api
http://www.snipsnap.org/RPC2
http://xmlrpc.blogg.de
http://xping.pubsub.com/ping/
http://a2b.cc/setloc/bp.a2b
http://api.mw.net.tw/RPC2
http://blog.with2.net/ping.php
http://blogbot.dk/io/xml-rpc.php
http://blogdigger.com/RPC2
http://blogoole.com/ping
http://blogoon.net/ping
http://blogpeople.net/servlet/weblogUpdates
http://blogsdominicanos.com/ping
http://blogsearch.google.ae/ping/RPC2
http://blogsearch.google.at/ping/RPC2
http://blogsearch.google.be/ping/RPC2
http://blogsearch.google.bg/ping/RPC2
http://blogsearch.google.ca/ping/RPC2
http://blogsearch.google.ch/ping/RPC2
http://blogsearch.google.cl/ping/RPC2
http://blogsearch.google.co.cr/ping/RPC2
http://blogsearch.google.co.hu/ping/RPC2
http://blogsearch.google.co.id/ping/RPC2
http://blogsearch.google.co.il/ping/RPC2
http://blogsearch.google.co.in/ping/RPC2
http://blogsearch.google.co.it/ping/RPC2
http://blogsearch.google.co.jp/ping/RPC2
http://blogsearch.google.co.ma/ping/RPC2
http://blogsearch.google.co.nz/ping/RPC2
http://blogsearch.google.co.th/ping/RPC2
http://blogsearch.google.co.uk/ping/RPC2
http://blogsearch.google.co.uk/pingRPC2
http://blogsearch.google.co.ve/ping/RPC2
http://blogsearch.google.co.za/ping/RPC2
http://blogsearch.google.com.ar/ping/RPC2
http://blogsearch.google.com.au/ping/RPC2
http://blogsearch.google.com.br/ping/RPC2
http://blogsearch.google.com.co/ping/RPC2
http://blogsearch.google.com.do/ping/RPC2
http://blogsearch.google.com.mx/ping/RPC2
http://blogsearch.google.com.my/ping/RPC2
http://blogsearch.google.com.pe/ping/RPC2
http://blogsearch.google.com.sa/ping/RPC2
http://blogsearch.google.com.sg/ping/RPC2
http://blogsearch.google.com.tr/ping/RPC2
http://blogsearch.google.com.tw/ping/RPC2
http://blogsearch.google.com.ua/ping/RPC2
http://blogsearch.google.com.uy/ping/RPC2
http://blogsearch.google.com.vn/ping/RPC2
http://blogsearch.google.de/ping/RPC2
http://blogsearch.google.es/ping/RPC2
http://blogsearch.google.fi/ping/RPC2
http://blogsearch.google.fr/ping/RPC2
http://blogsearch.google.gr/ping/RPC2
http://blogsearch.google.hr/ping/RPC2
http://blogsearch.google.ie/ping/RPC2
http://blogsearch.google.in/ping/RPC2
http://blogsearch.google.it/ping/RPC2
http://blogsearch.google.jp/ping/RPC2
http://blogsearch.google.lt/ping/RPC2
http://blogsearch.google.nl/ping/RPC2
http://blogsearch.google.pl/ping/RPC2
http://blogsearch.google.pt/ping/RPC2
http://blogsearch.google.ro/ping/RPC2
http://blogsearch.google.ru/ping/RPC2
http://blogsearch.google.se/ping/RPC2
http://blogsearch.google.sk/ping/RPC2
http://blogsearch.google.tw/ping/RPC2
http://blogsearch.google.us/ping/RPC2
http://blogshares.com/rpc.php
http://blogsnow.com/ping
http://blogstreet.com/xrbin/xmlrpc.cgi
http://catapings.com/ping.php
http://effbot.org/rpc/ping.cgi
http://feedsky.com/api/RPC2
http://fgiasson.com/pings/ping.php
http://focuslook.com/ping
http://holycowdude.com/rpc/ping
http://imblogs.net/ping
http://j-ranking.com/ping.cgi
http://lasermemory.com/lsrpc
http://mod-pubsub.org/ping.php
http://newsisfree.com/RPCCloud
http://newsisfree.com/xmlrpctest.php
http://ping.amagle.com
http://ping.blogg.de
http://ping.blogoon.net/
http://ping.blogs.yandex.ru/RPC2
http://ping.fakapster.com/rpc
http://ping.fc2.com/
http://ping.gpost.info/xmlrpc
http://ping.kutsulog.net/
http://ping.namaan.net/rpc
http://ping.speenee.com/xmlrpc
http://ping.weblogs.se
http://ping.wordblog.de
http://pinger.blogflux.com/rpc
http://pinger.onejavastreet.com
http://pingqueue.com/rpc
http://queerfilter.com/ping
http://r.hatena.ne.jp/rpc
http://rcs.datashed.net/RPC2
http://rpc.britblog.com
http://rpc.icerocket.com:10080
http://rpc.newsgator.com
http://rpc.reader.livedoor.com/ping
http://rpc.wpkeys.com
http://rssfeeds.com/suggest_wizzard.php
http://rssfwd.com/xmlrpc/api
http://serenebach.net/rep.cgi
http://snipsnap.org/RPC2
http://thingamablog.sourceforge.net/ping.php
http://wasalive.com/ping
http://weblogalot.com/ping
http://weblogues.com/RPC
http://xianguo.com/xmlrpc/ping.php
http://zhuaxia.com/rpc/server.php
http://blogupdate.org/sverige/ping/
http://blo.gs/ping.php
http://ping.feeds.yahoo.com/RPC2/
http://pingoat.com/
http://rpc.pingomatic.com
http://zing.zingfast.com
http://www.zhuaxia.com/rpc/server.php
http://www.xianguo.com/xmlrpc/ping.php
http://www.weblogues.com
http://www.snipsnap.org
http://www.popdex.com
http://www.mod-pubsub.org/ping.php
http://www.lasermemory.com
http://www.holycowdude.com/rpc/ping/
http://www.feedsky.com/api/RPC2
http://www.catapings.com/ping.php
http://www.blogsdominicanos.com/ping/
http://www.blogroots.com
http://www.blogpeople.net
http://www.a2b.cc
http://weblogues.com/RPC/
http://weblogues.com/ping/
http://wasalive.com/ping/
http://topicexchange.com
http://syndic8.com/xmlrpc.php
http://rpc.twingly.com
http://rpc.technorati.jp/rpc/ping
http://rpc.bloggerei.de/ping/
http://rcs.datashed.net
http://popdex.com/addsite.php
http://ping.wordblog.de/
http://ping.snap.com/ping/RPC2
http://packetmonster.net/xmlrpc.php
http://newsblog.jungleboots.org/ping.php
http://mod-pubsub.org
http://lasermemory.com/lsrpc/
http://imblogs.net/ping/
http://holycowdude.com/rpc/ping/
http://hamo-search.com/ping.php
http://bulkfeeds.net
http://blogupdate.org/ping/
http://blogroots.com/tb_populi.blog?id=1
http://blogpeople.net/ping
http://blogoon.net/ping/
http://blogoole.com/ping/
http://blogdb.jp
http://blog.goo.ne.jp
http://bitacoras.net/ping/
http://bitacoles.net/ping.php
http://bitacoles.net/notificacio.php
http://bblog.comping.php
http://audiorpc.weblogs.com/RPC2
http://api.my.yahoo.com/ping
http://api.my.yahoo.co.jp/RPC2
http://www.a2b.cc/setloc/bp.a2b
http://xping.pubsub.com/ping
http://blog.youdao.com/ping/RP2
WordPress keeps a fairly good list of these service at the Codex, which is the technical lexicon for all things WP. You can also find a link to this page on the Settings/Writing page within WordPress.
Using Smart Update Pinger plugin will ping these services only when you post the article not when you edit it—saving your server processing time. This plugin also allows you to check its “smart-update-pinger.log” file in the wp-content folder to see if any services are refusing ping requests from your site. You can remove these services as another way to save on processing time.

