Why we use ping after blog post?

The benefit of pinging is basically when you let the search engines know that you have updated your blog or website. So if you want to promote traffic, a ping after each update is very necessary because search engines feast on fresh quality contents.
Pinging is the best way to notify the search engine that you've updated something new at your website and search engine index them quickly.

Pinging 101: The Importance of Pinging Your Blog
If you just started blogging there is a strong possibility that you still don’t know what Pinging is. Pinging is basically when you let the search engines know that you have updated your blog. Search engines feast on fresh new content, so a ping after every new blog post is a must if you want to promote traffic.

How do I ping?
You can use Pinging services such as Ping-o-matic, Pingoat, or Feedshark. The process is very simple, you fill in your blog’s title, URL, RSS feed, and hit the ping button, that’s it! For those of you that would prefer your blog to ping automatically, blogging platform such as WordPress and Blogger have their own built in pinging option. Regardless of what blogging platform you use, it is important to make sure not to over ping, which can cause your blog to be banned by Pinging services and labeled as spam. WordPress users can do this simply by adding a plugin called MBP Ping Optimizer, which prevents your blog from overpinging itself to death.
Pinging should become part of every blogger’s regimen. A blog post and a ping are just like peanut butter and jelly; it’s hard to have one without the other.

Posted in: SEO-Search-Engine-Optimization