Google: structured data doesn't provide unique information

#1
During our last webmaster hangout, Google employee John Mueller talked about the role structured data plays in understanding web pages.

According to Mueller, the search engine receives all the necessary information about the page directly from the page and rarely learns something new from the semantic markup. In doing so, Google only takes into account the structured data that is supported in search and uses it to create rich results.

The question for Mueller was about the benefits of using structured data that is not mentioned in the official Google docs.

He replied that from a ranking point of view, this does not provide any advantages, but there is no harm in it either. However, it is better to focus on the kind of data that is supported by the search engine:

“We generally recommend using structured data for items that you would like to make visible in search results. And this visible data is based on the properties that we have documented. "
Google crawls structured data in order to display this information in search results, not in order to learn something new about the page:

"So if you add structured data for things that we don't use for rich results, then we can crawl those pages normally, but we just don't use that extra information."
You can listen to the question to Mueller and his answer to it in the video: