Although AMP is not a ranking factor, non-compliant page will no longer appear in Top Stories and other AMP-related search features.
Google has announced that as of the start of February 2018, Accelerated Mobile Pages (AMP) and canonical pages must match or at least have very "close parity". AMP pages that fail to comply "will not be considered for Search features that require AMP, such as the Top Stories carousel".
It has always been a requirement for AMP pages to have matching content to their canoncial page, but now Google is prepared to penalise pages that do not comply - although they are keen to emphasise that AMP is not a ranking factor.
The reason Google is planning to penalise pages is that AMP is increasingly being used by publishers on "teaser pages" that offer limited content. Google says:
In some cases, webmasters publish two versions of their content: a canonical page that is not based on AMP and an AMP page. In the ideal scenario, both these pages have equivalent content leading the user to get the same content but with a faster and smoother experience via AMP. However, in some cases the content on the AMP page does not match the content on its original (canonical) page.
In a small number of cases, AMP pages are used as teaser pages which create a particularly bad user experience since they only contain minimal content. In these instances, users have to click twice to get to the real content.
Google uses the below example of a news article which features a call to action to click for the "full story" - which sends mobile users to a non-AMP page.
From February 1 2018, when Google spots a non-compliant AMP page it will send searchers to the "non-AMP equivalent" canonical page and notify the webmaster via the Search Console as a manual action message.
About the Author
Luke Glassford is an SEO expert with over 15 years’ experience.
During his time working in SEO, Luke has set-up an SEO agency, worked as an in-house SEO for a major national company and managed his own successful SEO consultancy - using a lot of different SEO tools along the way!