Google’s John Mueller listed a few reasons why your site may not show rich results in the Google Search Results. One of the three reasons is that sometimes Google does not trust the site enough, on the site level, for Google to warrant that the site shows rich results.

John said in a video hangout at the 15:38 mark he said one of the reasons rich results won’t show is “usually sitewide signal that is about the quality of the site overall.” John explained “Like can we trust this website to provide something reasonable with structured data that we can show in the rich results? And usually what happens when everything from a technical point of view is set up correctly and we’ve had enough time to process it for indexing and it’s still not shown, then that’s usually a sign that our quality algorithms around the rich results in general are not 100% happy with your website.”

The other reasons can be technical issues, either the structured data is invalid or the content on the page does not reflect what the structured data shows.

Here is the video embed:

Here is how Glenn Gabe summed it up:

Here is the transcript:

Forum discussion at Twitter.