If I write a blog post in reply to somebody else’s blog post, there should be a link back to my post from the one I commented on.
Trackbacks are used primarily to facilitate communication between blogs; if a blogger writes a new entry commenting on, or referring to, an entry found at another blog, and both blogging tools support the TrackBack protocol, then the commenting blogger can notify the other blog with a “TrackBack ping“; the receiving blog will typically display summaries of, and links to, all the commenting entries below the original entry. This allows for conversations spanning several blogs that readers can easily follow.
Via Wikipedia
You recoil at the spamminess of this, I know. Yes, this leads to more spam than ham. That is why the world does not work this way. Trackback is dead.
Some individuals or companies have abused the TrackBack feature to insert spam links on some blogs. This is similar to comment spam but avoids some of the safeguards designed to stop the latter practice. As a result, TrackBack spam filters similar to those implemented against comment spam now exist in many weblog publishing systems. Many blogs have stopped using trackbacks because dealing with spam became too much of a burden.[citation needed]
Wikipedia again
It is also true but irrelevant that spam is an AI for truthtelling.
Trackback has nasty technical problems, and for that reason there are a number of alternative protocols, such as (notably) Webmention. (Here’s a good article on all the options: Linkback).
But spam is the blocker, and it’s so bad that none of the options gets used much. That’s really really really too bad, because linkbacks are critical for a lively and vital ecosystem of decentralized social networking.
It doesn’t have to be this way. There is a trivial solution to all linkback spam: a whitelist of friends, such as you find in a blogroll.
I envision a WordPress plugin with these features:
- On the inbound side, it receives and displays linkbacks. On the outbound side it sends them.
- When a linkback is received, it checks the whitelist. If the sender is whitelisted, it is auto-approved. Otherwise the linkback goes into the spam queue for manual approval.
- When a linkback is manually approved, the source site goes into the whitelist.
- Maintain a blogroll. Allow the blog owner to add sites. Display the blogroll. Use the blogroll to populate the white list.
P.S. On this blog I have a plug-in which implements Webmention linkbacks, but to my knowledge this has never caused any outbound or inbound linking. The only utility of this plugin is that it helps me signal that I approve of the protocol design.