From the looks of it, it seems as though sites with low value content were hit hard by this update. Examples of “low value” sites would include websites that:
– Contain heavy advertising (particularly banner ads)
– Have a small amount of content or just poor quality content
– Lack any real value for the user
– Contain irrelevant links
Short articles (300 words or less) stuffed with main keywords (that at times are hard to make any real sense of), were also affected by Google’s Fred update. Blog sites that cover every possible topic on Earth that have already been written about by others in the industry will have been penalized by this update, as well. Many blog sites are created for the sole purpose of ranking and therefore, they often provide very little value to the reader. The good news is that the legit websites that do offer unique quality content to their readers will likely see a boost in ranking, as the spammy sites wither away from Google’s search results.
Visit https://support.google.com/webmasters/answer/35769?hl=en for more details on Google’s Webmaster Guidelines.