ping is a way to increase the indexing time and cache them. This is the best way to improve the website visibility in search engine. You should participate in pinging services for fast indexing of the website.
Pinging submission is basically an automatic notification to a search engine, that a page has been updated and it should be recrawled. Specifically, this is relevant for social sites like, forums blogs and other web 2.0 sites that are indexed by several search engines that keep a record of the page and the date.