I think I’ve always been clear that webmasters can do whatever they want on their own site. But I’ve also tried to be clear that I believe Google has the right to defend our search results from low-quality or spam results in our opinion. So when I do a post like this, I’m trying to provide guidance on the sort of behavior or activity that Google would prefer not to reward. From where I’m sitting, there’s enough spam taking place under the rubric of “guest blogging” that I wanted to provide people with a heads up.
But you can always do whatever you like on your website, in the same way that Google is able to decide not to return a website in our search results if we believe it should rank lower or shouldn’t be returned.
Take care!