I've been working with WordPress blogs for a while, but I'm still a bit perplexed about the value of a trackback link on blog pages. The link needs to be blocked in the robots.txt file or the blog may get indexed twice. Yahoo seems to ignore the robots.txt file and lists the trackback links in their index anyway. I've been told that WordPress uses it to determine who is linking to your site, but it doesn't make much sense to have someone link to a page with a URL that is different from the primary URL. I see a multitude of problems associated with a trackback link. I don't see any value or the purpose for having these links. I am talking about the links on a WordPress blog page that end with /trackback/ What is the purpose for these links? Is there any value with leaving these links on a page? I'm looking for a good explanation of what a trackback is and how it benefits a site.
I have been wondering about this for a while. I think the biggest thing about trackbacks is a duel partnership. One person realizing the value of a post and linking to it and in return getting a recip back. I may be wrong but this is my interpretation.
It's just a way of letting you know that there is a post on another site referring to your post. That's the only purpose it serves. It's up to you to decide it's value.
The trackback link does have a rel="trackback" attribute. I assume that this is the equivalent of rel="nofollow", but I have never seen it described that way.