The post was widely misinterpreted to mean "stop doing guest blogging," as even Matt acknowledged in a later addition to his original post:
"I'm not trying to throw the baby out with the bath water. There are still many good reasons to do some guest blogging (exposure, branding, increased reach, community, etc.). Those reasons existed way before Google and they'll continue into the future. And there are absolutely some fantastic, high-quality guest bloggers out there. ..I just want to highlight that a bunch of low-quality or spam sites have latched on to 'guest blogging' as their link-building strategy, and we see a lot more spammy attempts to do guest blogging. Because of that, I'd recommend skepticism (or at least caution) when someone reaches out and offers you a guest blog article."
The point is pretty clear. Guest posting done with the interest of the community and readers in mind still have value. But attempts at getting guest posts published in a manipulative manner, purely or primarily for the SEO benefit of the backlink, are no longer going to be effective (and by implication, may even lead to penalties or ranking degradation).
And the gray area isn't even that large; it's generally fairly easy to separate legitimate guest post requests from the spammy ones.
Sender: legitimate guest post requests will generally come from people you know, or have heard of, or who at least seem to have a reputable online presence and can tell you exactly why they want to write for your blog (beyond just "Hey, I love your blog!").
Relevance: a legitimate request will generally focus on one specific post, suitable for your audience and relevant to your typical topics and style. For example, this post on fascinating social media facts and statistics was a great fit for Jeff Bullas' blog, because it meshes well both topically and stylistically with the kinds of posts Jeff often writes. But this style would not have worked as well on a site like Social Media Examiner.
Spammy guest posters, on the other hand, are often miraculously able to write a post on any topic from household cleaning tips to space travel-or a custom topic if you prefer! Ugh.
Compensation: Matt calls this out specifically in his post, noting that "email offering money to get links that pass PageRank (are) a clear violation of Google's quality guidelines." A legitimate guest blogger offers a post that has value to your blog in and of itself, and so would not propose monetary compensation.
Backlinks: virtually all guest posts include backlinks. Nothing wrong with that alone. The difference here between a legitimate and a spammy request is 1) the purpose of the links: do they appear to be there to guide the reader to additional, relevant information-or are they trying to sell something, or link to a page with little or no relevance to the post? (or worse, to something sketchy like an online pharmacy site); and 2) the author's approach to the links. If he or she is comfortable with you changing, deleting, or no-following the links, then the guest post is clearly not just a spammy attempt at link building.
Comfort level: this is a bit amorphous, and will vary among individuals, but essentially: based on what you know about the person proposing the guest post, would you be open to connecting with him or her on various social media platforms? Possibly even to-under the right circumstances-write your own guest post for that person's blog?
For example, there's been some cross-posting over the years between Webbiquity and the Blue Focus Marketing blog. The cross-posting is decidedly non-spammy because both blogs focus on b2b marketing and branding; Cheryl and Mark are excellent writers and authors; and they are awesome people. It would make sense even in the absence of any SEO benefit (though there likely is, still, some).
Motivation: as Matt notes in the addition to his original post quoted above, "There are still many good reasons to do guest blogging." It increases brand awareness, provides the opportunity to connect with a new audience, and helps increase overall web presence for a brand or product.
And Matt's post doesn't specifically say that no type of guest blogging still provides some SEO benefit-only that guest-blogging is no longer effective as a large scale link-building strategy, and that he would "recommend skepticism (or at least caution) when someone reaches out and offers you a guest blog article."
While Google can't look into a blogger's heart to determine true motivation, it can and presumably will continue to look at characteristics like a site's overall link profile (do guest post links make up an inordinate share of all backlinks?) and the quality of linking sites in determining rankings.
This latest development will also likely increase the importance of Google Authorship as a way to separate legitimate guest authors from spammers.
In short, guest blogging is not dead. Far from it. The only thing that has died is the practice of generating large numbers of backlinks through spammy email outreach for guest posts. And good riddance.