Pinging is alerting search engines about the updates you made in your website and this alert helps your new contents to be indexed faster.

agree with jabx123, it helps to index quickly

Just wanted to add another site that may help you.

pingfarm works well for bulk functioning as well.

simple as pinging or reminding search engines for your updates or even a brand new sites as well.

Comsider also BulkPing.com and PingDevice.com for mass pinging to get your backlinks indexed quickly.

Pinging doesn't work though. Don't spend your time doing it.

Use a larger ling list in your wordpress notification list and yes, pinging will help you. If you use the default list, it is very limited. Every time you post, it will update and notify.