Today, over at Jojo‘s I was able to read that Webnews, this Digg-clone which might have been noticeably too late but who, in return, started with Samwergeld, got this funny idea to send trackbacks when you submit your news there. If we just leave out the whole Web2.0-front and think about what is actually happening, then we can only view this behavior as a pure form of spam: someone write a blog/news article and is thereby creating content. Now we have a second person who copies this content (partially) onto their own site. The original content is still pinged for a few external links. A procedure that is popular and successful with spammers for years.
The idea behind trackbacks is that if, in your own (!) new (!) article, you are referring to an opinion in another blog, you can let the creator know. It is, however, not to increase the traffic to your own site.