Ping is simply a program that sends a message to another server or computer to get a response. So if you update your blog, simply pinging so that your pages are indexed by search engines and blogs you can get backlinks to get a chance to rank higher. Regarding the definition of ping can be read in wikipedia about Ping (blog). Read : Tips to get thousand backlink
With Ping Can Quickly Indexed, Get Backlinks & Traffic
Keep in mind, that if your blog or website does not appear in the search engine most likely because it has not indexed so it is not possible to get traffic. So, the best thing to do is to ping and your blog will get indexed significantly and faster.
About the site where you have to ping your blog remedy, I recommend Free Backlink Tool. You can begin to build backlinks and get up to 500 links that lead directly to your blog or website.
Below are the current best PING site: