This Pingback informs all the sites like Feedburner, Google Blog Search, etc, that you have updated something on your blog....
pingback is a web service that can perform an index on your site. Its main purpose is certainly to your site can be tracked in search engines and of course this would increase the index pages on your website.
A pingback happens when another blogger writes a post and includes a link to your post in their post. When they publish their post you’ll normally receive an email notification letting you know they have referenced (i.e. linked to) your post. The email notification commonly includes an extract from the post they’ve written, a link to their post and a link to the post you had written.
The Pingback system is a way for a blog to be automatically notified when other blogs link to it. It is entirely transparent to the blogger doing the linking, requiring no user intervention to work, and operates on principles of automatic discovery of everything that it needs to know. A sample blog post involving Pingback might go like this: 1. Alice posts to her blog. The post she's made includes a link to a post on Bob's blog. 2. Alice's blogging system contacts Bob's blogging system and says, "look, Alice made a post which linked to one of your posts!" 3. Bob's blogging system then, when people view the posts on Bob's blog, notes on the page that Alice linked to this post. 4. Users can then follow this link back to Alice's post and read more.