Black Hat SEO and AMP Abuse
Google heralded its Accelerated Mobile Pages (AMP) project as a lightweight version of websites that used a lot less bandwidth.
Some websites, however, are taking advantage of the technology, deliberately including less content in their AMP versions with a link to the original page.
Why would a website do that? Simple, Google shows AMP pages in its carousel and SEOs are no dummies. By securing their position on the search results page they can increase their visibility and get users to click through to the full version of their website - and the ads that support them.
Using 'teaser' content in this way forces users to click through to see the full page. But Google sees this bait-and-switching as infringing on AMP's mission to 'dramatically improve the performance of the web and deliver a fast, consistent content consumption experience,' as the search giant's blog post put it.
The practice did not go unnoticed by Google, of course, and Google announced that by February 2018, AMP pages and their source counterparts must have identical material. That should put an end to the practice for now.
Google assured that, after the February 2018 deadline, should the lightweight AMP version be incomplete compared to the source material, a link will redirect visitors to the original page. This won't affect those pages' Search ranking, and Google will invite those webmasters to fix the shortened edition.