Spam spam spam spam
What possible benefit can comment or trackback spam be to anyone?
I wonder what would happen if i attempted to do business with one of the companies linked to in the spam i get, then hunted them down and gave them an involuntary vasectomy?

If I ever capture one of ’em…want some?
Save me something with a lot of nerve endings.
You can always expose new nerves with a wire brush after you killed those previously exposed with the propane torch. Just remember to keep giving them plenty of fluids to keep the shock from being fatal.
yeah, you gotta hook up the IV beforehand.
As I understand it — and Internet programming is NOT my specialty — some of the search engines rank you based on incoming links to your site. Google never releases their ranking algorithm, but this is rumored to be part of it.
So a trackback spammer is attempting to boost his Google ranking, at your expense. After all, every one of those trackbacks is a link to his site.
They usually try to be clever, by adding trackbacks to very old posts, posts you may never look at again. That way, the trackbacks can linger. The search engines don’t care about old vs. new posts, after all.
They used to rely more on mere comment spam, with links in the comments. But now lots of blog systems put Human Detection Filters on their comment pages, and others simply disallow links. The comment spam isn’t as reliable as it once was. So now they’re relying more on trackbacks, where they have more control.
Now the really dumb thing about this is: the search engine folks are aware of this game, and they’re tweaking their algorithms to deemphasize or even ignore trackback links. They don’t like it when people game their algorithms, and they work hard to be sure it will fail.
So these idiots are consuming your bandwidth and your storage space in an effort that won’t get them what they’re after. Utter, absolute idiots.