Well I came across a real gem of a post earlier, from no less than Rand Fishkin, former CEO of Moz.
He's got very hot under the collar with Google, after they penalised one of the Moz contributors for violating Googles Quality Guidelines!
You can read the full article here, and it's well worth a read. Once you get into it, it's not as clear cut as Rand suggests, and Google aren't penalising Moz.com, rather a personal website of a contributor. After more investigation by Search Engine Lands Danny Sullivan, suggests the website has a possible history of keyword rich anchor text in blog posts and articles.
Implications for Guest Posts and Articles
But let me break down what it's saying and the implications straight from Googles mouth via Matt Cutts (head of Google webspam).
An author who has published a guest article on a Moz Blog has been penalised by Google for not following Googles link building guidelines, of which they have given a few examples, including a link to Moz.
Anyone who is currently guest posting, article writing or about to, stop, read and digest!
To me this is no surprise, as we get a few link removal requests from penalised site owners, as the Google linking hysteria reaches a crescendo, and webmasters in a panic decide to remove all of their links!
But to hear the likes of Moz.com have the same issue just confirms what a mess the system is in, and the whole ethos of linking, the cornerstone of the internet is now fundamentally flawed.
We had to amend our policy last year and make links from our directory "nofollow". nofollow simply means adding a bit of code to all outbound links, which tells Googles web crawler to ignore the link, which means things like PageRank won't flow down the link, and the link won't be counted in your linking profile.
There isn't a "follow" code, as links do this by default.
In the same vain we have made the forum "nofollow" to ensure that anyone who links from their signature or anyone we link to is safe and not impacted with any potential or future algorithm penalties, and likewise protects us from any sites we link to who Google deem to be unsavoury.
I was worried if this was the right path to go down, as it goes against the spirit of the internet, but after many discussions with other site owners and marketing teams, including some large directories, this is the route we went.
But Matt Cutts seems to finally confirm that just about everything is to be "nofollow".
This is the response Matt Cutts made when interviewed by one of Moz's Directors, albeit a few months before this incident.
Matt Cutts: "Hey, the short answer is that if a site A links to spammy sites, that can affect site A's reputation. That shouldn't be a shock--I think we've talked about the hazards of linking to bad neighborhoods for a decade or so...
...The factors that make things safer are the commonsense things you'd expect, e.g. adding a nofollow will eliminate the linking issue completely. Short of that, keyword rich anchortext is higher risk than navigational anchortext like a person or site's name, and so on."
So if you are creating an article or blog post that will go on someone else's site, then common-sense now dictates for safetys sake that any links are set as "nofollow".
Is Guest Posting or Article Writing Dead?
This now depends on your perspective 
For SEO purposes, ie simple link building then yes. Articles for sometime, and now more recently guest posting.
But the whole SEO approach and obsession of link building is now breathing it's last dying breath of air, and thank goodness!
It's time to go back to marketing. Search Engine webcrawlers, bots and spiders aren't the only things that click links. If you write an informative, interesting or informational blog post or article, that sets you up as an industry expert or someone who at least has an idea of what they are talking about, then the chances are, humans will click any links you have in your content to learn more.
Good content generates targeted traffic. Marketing 101. Always has, always will, regardless of whatever Google Panda, Penguin or Percy Pig it rolls out next.
So revise your policy, be selective where you add your content. If it's still offering "follow" links, then be very careful how you create your links. Be very wary of generating links that can be perceived as keywords.
If a site is offering guest posting, but is nofollow links, then you know you are safe from penalties, but is the site worth you adding your hard crafted content? How many human eyeballs will view your content.
Don't forget, regardless of how a link is constructed, follow or nofollow, your analytics will tell you how successful a post has been and which sites are generating you targeted content.
Summary
Moz.com isn't a spammy site, and isn't being penalised as one. An author is being penalised, but based on his wider linking profile. Inadequate tools have simply flagged up a moz link as an example of a bad one. In war this is called friendly fire or blue on blue.
But the use of nofollow links, even though it goes against the very fabric of the web is now set to increase tenfold.
Guest posting is a superb means of marketing, but target a human audience not a search engine one. Let the practices of yesteryear link building and keyword rich anchor text disappear, and if you have a chance, maybe have a look at your own linking profile if you suspect you may have abused it a little in the past.
Semi Sales Pitch (I'm allowed)
If you want to see an example of eyeballs on a blog post, then look at our Forum Blog. Look at the views versus the posting date. All links within the post are nofollow, and if there was a relevant link in the forum signature, or byline to your site, how many visitors would you be getting?
