Yesterday Matt Cutts posted a clear message on his personal blog that guest posting is dead. He said "if you're using guest blogging as a way to gain links in 2014, you should probably stop....I'd expect Google's web-spam team to take a pretty dim view of guest blogging going forward".
Google has been issuing warning about this practice to get links in the past. In July 2013, Google's John Mueller said "it is best you nofollow links in stories you write, especially when those stories are guest blog posts for the purpose of link building". In October 2013, Matt said "guest blogging best done in moderation". Then in Dec. 2013, Matt noted in a video that guest blogging abuse and spam is on the rise.
Now he says in no uncertain terms : " So stick a fork in it: guest blogging is done; it's just gotten too spammy... I wouldn't recommend relying on guest posting, guest blogging sites, or guest blogging SEO as a link building strategy".
As a caveat, he accepts that there are genuine reasons to do write guest blog posts such as exposure, branding and increased reach. Going forward, do not be surprised if Google unleashes an algorithmic update that penalizes guest blogging. What you need to do is stay away from low-quality or spam sites or indulge in guest blogging on large scale.
