There is a chance that your pages have been logged in to GSC or Google Search Console that receives alerts on a regular basis from Google regarding page problems. These alerts can range from anything such as search reports of the previous month, inaccessibility of a page, and mobile site problems. It means that many of you are used to getting these alerts that you no longer pay attention to them.
If so, it is likely that you overlooked or even failed to receive the latest message from GSC last March 2019 that is somewhat different from previous alerts.
What message from GSC means?
The message from GSC means that Google already started considering structural information as one factor in page quality. This is something that has been under monitoring ever since the expansive mobile search engine switch that happened last August.
When you speak of structural data, it means that the pages include additional information in a particular product case. The information cannot be seen on the page as this is included in the code. A good example is from the Structural Data Testing Tool of Google https://search.google.com/structured-data/testing-tool/u/0/.
It may seem quite complicated but you don’t have to worry
Most of the time, the issue can be solved with the installation of the right plugin. WordPress, for instance, supports Yoast basics installed on many WordPress installations. There are also dedicated plugins such as https://wordpress.org/plugins/schema-and-structured-data-for-wp/.
This is also applicable to the rest of the CMSs
For Magento Amasty (https://amasty.com/magento-google-rich-snippets.htm/) or Magmodules (https://www.magmodules.eu/schema-org-rich-snippets.html) being the most popular plugin developer but there are still a lot more.
The solutions are available for all systems. These come at affordable prices and some are even free. Make sure you install them right away.