The other day, it was reported that over the weekend that Google had sent out outbound linking penalties to a mass number of webmasters. More information came out saying that this was directly related to the warning from Google gave a number of weeks ago for any bloggers to disclose free product reviews as such and nofollow links in their posts over these reviews.
Google told bloggers to “nofollow the link, if you decide to link to the company’s site, the company’s social media accounts, an online merchant’s page that sells the product, a review service’s page featuring reviews of the product or the company’s mobile app in an app store.”
After the warning was sent out to everybody, Google sent out manual actions for those who don’t comply with these guidelines a few weeks later.
There were some threads that John Mueller commented on in the Google support forums where he told people to look at the warning Google published all those weeks ago named Best practices for bloggers reviewing free products they receive from companies. one of the comments he left was:
In particular, if a post was made because of a free product (or free service, or just paid, etc.), then any links placed there because of that need to have a rel=nofollow attached to them. This includes links to the product itself, any sales pages (such as on Amazon), affiliate links, social media profiles, etc. that are associated with that post. Additionally, I imagine your readers would also appreciate it if those posts were labeled appropriately. It’s fine to keep these kinds of posts up, sometimes there’s a lot of useful information in them! However, the links in those posts specifically need to be modified so that they don’t pass PageRank (by using the rel=nofollow).
Once these links are cleaned up appropriately, feel free to submit a reconsideration request, so that the webspam team can double-check and remove the manual action.
Source – Barry Schwartz