It's Matt Cutts video time again. This time, he answers the question: "How can I guest blog without it looking like I pay for links?"
"Let's talk about, for example, whenever we get a spam report, and we dig into it in the manual webspam team, usually there's a pretty clear distinction between an occasional guest blog versus someone who is doing large scale pay-for-links kinds of stuff," he says, "So what are the different criteria on that spectrum? So, you know, if you're paying for links, it's more likely that it's off topic or an irrelevant blog post that doesn't really match the subject of the blog itself, it's more likely you'll see the keyword-rich anchor text, you know, that sort of thing. Whereas a guest blog, it's more likely to be someone that's expert, you know. There will usually be something - a paragraph there that talks about who this person is, why you invited them to be on your blog. You know, hopefully the guest blogger isn't dropping keywords in their anchors nearly as much as you know, these other sorts of methods of generating links."
"So it is interesting," he continues. "In all of these cases, you can see a spectrum of quality. You can have paid links with,you know, buy cheap viagra, all that sort of stuff. You can have article marketing, where somebody doesn't even have a relationship with the blog, and they just write an article - 500 words or whatever - and they embed their keyword-rich anchor text in their bio or something like that, and then you've got guest blogging, which, you know, can be low quality, and frankly, I think there's been a growth of low quality guest blogging recently. Or it can be higher quality stuff where someone really is an expert, and you really do want their opinion on something that's especially interesting or relevant to your blog's audience."
These are the kinds of criteria Google looks at when trying to determine if something is spam, Cutts says. He also cautions against spinning content for contribution on a bunch of blogs. That's not the best way to build links, he says.
Go here for more past comments from Google related to guest blog posts.