How it works
Be sure to read the documentation found in the manual to truly understand how TrackBack works. Here is a short and simple example of TrackBack in use (or course, minus the context of any real content)
This is just a regular weblog post with "allow pings" turned on. Imagine that I have written something terribly important, witty or enlightening.
Now, after reading this, you decide that you want to write your own post on your weblog that references this entry -- the normal sort of weblogging referencing that we're all used to seeing and doing.
Now, since you've decided to write or reference the original post and because you're eventually going to have to ping the site, you're going to need the ping URL of this post.
Currently, there are two ways to ping an entry. The first is to manually copy the ping from the TrackBack popup and paste it in the appropriate field of the new edit screen.
The second, much easier method involves using the bookmarklet. If you click on the Movable Type bookmarklet while on a page that contains a TrackBack-enabled entry, the bookmarklet will display a list of TrackBack-enabled entries. You can select the entry that you wish to ping from a pull-down menu.
Now, try to ping this entry.
Additionally, we have the category TrackBack set up in the right column of this blog. To ping this category, associate this url with a category called TrackBack:
http://www.movabletype.org/mt/mt-tb.cgi?tb_id=3
Note, you can call the category whatever you want -- TrackBack just makes sense for this instance.
Possible Uses Of TrackBack
We think that out of the box, the concept of TrackBack may be a bit confusing. It seems like the sort of feature that will start to make sense once MT users start to see real-life applications of feature.
But still, we've already thought of some examples where TrackBack can be used. It's certainly not just limited to pinging entries.
Multiple "authors" without author accounts
Say you want to have your readers contribute to your blog, but do not want to add them as an author; either because you want to limit the number of authors or you don't want the work of having to add new people each time someone wants to post something interesting. Or, you may not want their posts to "weigh" as much as your official set of multiple authors.
With TrackBack, you can set up a section of your site to receive pings.
Kristine, one of our beta-testers, used her site, The Red Kitchen, as an example:
"If I had a category named 'Red Kitchen Guests' and allowed pings to it... then anyone with an MT blog could post a recipe on their page and ping my guest category. Then it could automatically list a ping link and excerpt on the Guest category page."
Referencing Individual Entries
You write an interesting post. Someone wants to comment about your post or reference the link on their own blog. Instead of relying on referrals or a comment that says "I wrote about you," the person who commented would simply ping your entry.
As another beta-tester, Brenna, said, think about this an an extended comment that you store in your own database. It's a way to generate comment for *your own* site while continuing the conversation.
We've also developed a tool that will display a threaded view of the entries involved in a discussion across multiple blogs whose participants are using TrackBack. This will be a stand-alone tool, not contained in the Movable Type distribution. We should be releasing it soon.
Surveys & Question memes
On one site, a person provides a set of questions that he or she wants the weblogging community to answer on their own weblog (Think Friday Five, Monday Mission, Blogger Pride Survey). Once you have answered these questions, you usually return to the site and post a comment linking to your set of answers on your own blog.
Assuming that the question site uses MT & TrackBack, you can simply ping the original entry. On their site, your weblog name, permalink to the entry and possibly entry will show up in the TrackBack listing. All you had to do is save your entry.
Repositories of related content
Say you can't get enough of APIs. And, you want to start a repository that would be the greatest resource for people looking for discussions about the various APIs out there. So, you'd set up a repository page that would contain your categories and their ping URLs:
Google API
Amazon API
Blogger / MetaWeblog APIs
Those who spend a lot of time talking about these topics, would associate the ping URL to their own categories. So, every time they wrote about the Google API, they would simply select the category "Google API" (or whatever they call it) and press "save."
If someone knows about the category but only writes about it once in a blue moon, they could simple manually ping the category by using the entry pinging mechanism.