It appears that as of August 2013, Google is now going to target websites that are indulging in mass guest posts – IF the posts and/or the sites being posted to are of low quality and are not adding much value to readers.
There is now clear evidence that Google wants you to NoFollow your links in the content you post on other sites as Guests Posts.
Worth noting is the fact the new guidelines explicitly warn against large scale guest posting campaigns, paid advertisements, press releases and articles with optimized anchor text.
They have even updated their link schemes section inside Google Webmaster Guidelines. The guidelines now say that Large-scale article marketing or guest posting campaigns with keyword-rich anchor text links may negatively impact a site’s ranking in search results!
The bottom line: guest blogging done on a large scale may trigger a manual review, especially if the quality of the blog is in question. It now appears that guest blogging falls under the definition of unnatural linking – and, if you fail to nofollow the links, you may leave yourself open to manual penalties.
That said – Guest Posts can still give you a lot of juice, but you need to do it right and stay clear of the low quality signals that Google considers as webspam, and could thus trigger a manual review of your posts and backlink profile.
Here’s some tips…