How Trackbacks Work on a WordPress Blog

By Lisa Sabin-Wilson

The best way to understand trackbacks is to think of them as comments on your WordPress site, except for one thing: Trackbacks are comments that are left on your blog by other blogs, not by actual people. Sounds perfectly reasonable, doesn’t it? Actually, it does.

How blog trackbacks work

A trackback happens when you make a post on your blog, and within that post, you provide a link to a post made by another blogger in a different blog. When you publish that post, your blog sends a sort of electronic memo to the blog you’ve linked to. That blog receives the memo and posts an acknowledgment of receipt in a comment to the post that you linked to.

That memo is sent via a network ping — a tool used to test, or verify, whether a link is reachable across the Internet — from your site to the site you link to. This process works as long as both blogs support trackback protocol.

Sending a trackback to a blog is a nice way of telling the blogger that you like the information she presented in her blog post. All bloggers appreciate the receipt of trackbacks to their posts from other bloggers.

Beware of trackback spam

Ugh. The absolute bane of every blogger’s existence is comment and trackback spam. When blogging became the “it” thing on the Internet, spammers saw an opportunity. Think of the e-mail spam you’ve received — comment and trackback spam is similar and just as frustrating.

Before blogs came onto the scene, you often saw spammers filling Internet guestbooks with their links but not leaving any relevant comments. The reason is simple: websites receive higher rankings in the major search engines if they have multiple links coming in from other sites. Enter blog software, with comment and trackback technologies — prime breeding ground for millions of spammers.

Because comments and trackbacks are published to your site publicly — and usually with a link to the commenters’ websites — spammers get their site links posted on millions of blogs by creating programs that automatically seek websites with commenting systems and then hammering those systems with tons of comments that contain links back to their own sites.

No blogger likes spam. As a matter of fact, blogging services such as WordPress have spent untold hours in the name of stopping these spammers in their tracks, and for the most part, they’ve been successful. Every once in a while, however, spammers sneak through. Many spammers are offensive, and all of them are frustrating because they don’t contribute to the ongoing conversations.

All WordPress systems have one very major, very excellent thing in common: Akismet, which kills spam dead.