pingback

otherwise known as Linkback or Trackback, pingback allows one website to notify another about an update. It’s a method for website authors to request notification when somebody links to one of their documents; allowing them to keep track of who is linking to their articles. Sping or ping spam, is a ping that's sent from a spam blogs, or many pings sent in a short interval from a legitimate source (up to 100's per minute) in order to make the content coming from the source appear fresh.