Once upon a time, when the digital world was young and full of idealism, people would occasionally guest post on other people's blog, to comment on something they didn't normally write about, or to bring expertise into a different conversation.
Then, some people - let's call them "probloggers" - decided you could actually use this as a vast content pyramid scheme, by getting would-be bloggers to write posts for your blog. They hoped that they might get a trickle of your traffic, but you got free content to support your ads, so you didn't care much either way.
And then the SEO business noticed that these guest posts brought with them links, and links equal pagerank. And in that moment, guest posting contracted a terminal illness:
So stick a fork in it: guest blogging is done; it's just gotten too spammy. In general I wouldn't recommend accepting a guest blog post unless you are willing to vouch for someone personally or know them well. Likewise, I wouldn't recommend relying on guest posting, guest blogging sites, or guest blogging SEO as a linkbuilding strategy.
That's Matt Cutts of Google talking. But that sort of thing only carries weight if he gives a coded warning that an algorithm update is coming.
Oh, here it is...
So there you have it: the decay of a once-authentic way to reach people. Given how spammy it's become, I'd expect Google's webspam team to take a pretty dim view of guest blogging going forward.
I'm sure I've got a bottle of champagne around here somewhere...
Photo by Holly & Chris Melton and used under a Creative Commons licence