Google has today announced two new link attributes, rel="sponsored" and rel="ugc". Simply put, this will allow webmasters to tell Google Search that a particular link is located within sponsored content or user generated content (UGC) respectively.
Previously, Google had advised webmasters to to use rel="nofollow" for all links within sponsored content or risk a penalty for violating the search engine's quality guidelines. As the Google Webmaster Central Blog advised back in 2013:
"Make sure that any paid links on your site don't pass PageRank. You can remove any paid links or advertorial pages, or make sure that any paid hyperlinks have the rel="nofollow" attribute."
Although Google has confirmed that this approach will continue to be supported - if not favoured - what is slightly less clear is whether links marked as rel="sponsored" will pass PageRank (and yes, PageRank is still a thing). Let me expand on that a little.
At the same time as introducing the new link attributes, Google is changing to what it calls a "hint approach" or "hint model" both for these attributes and (from March 2020) the existing "nofollow" attribute. This means it can use these attributes "as hints about which links to consider or exclude within Search" (rather than completely ignoring the links as has been the case with "nofollow" up until now).
Google goes on to list some of the reasons why it might want to look at these links rather than completely ignore them, one of which is to "better understand unnatural linking patterns". So perhaps Google will be looking at sponsored content with rel="sponsored" links in order to better identify sponsored content elsewhere that is breaking its quality guidelines (by including links that have neither the "sponsored" nor "nofollow" attributes).
As a result, we may see more sites being penalised for 'selling links' - or more likely, having sold links in the past - through the medium of sponsored content.
Towards the end of its FAQs on the new attributes, Google adds:
"If you flag a UGC link or a non-ad link as “sponsored,” we’ll see that hint but the impact -- if any at all -- would be at most that we might not count the link as a credit for another page."
That 'might not' is interesting, as it suggests that links marked as 'sponsored' can, in some circumstances, pass PageRank. Whether that is simply because Google might sometimes ignore what it considers to be an incorrect 'sponsored' attribute, I'm not sure.
However I do know that if advertisers (and their agencies) believe - rightly or wrongly - that correctly attributed sponsored links do pass PageRank, then webmasters will be inundated with more sponsored content proposals than ever before.