Rich Snippets Only Displayed in Search Results if Required Conditions Are Met
Google will only show rich snippet results if the required conditions are met. This includes ensuring the markup is technically correct, which you can confirm using a testing tool, as well as making sure it is logically correct. The final requirement is ensuring the website contains quality content so that Google can trust the information that is being provided.
Changes to Review Rich Snippets Limit Available Review Types
The changes made to Review Rich Snippets means Google have limited the support to a certain set of markup types, as well as amending the approach to reviewing your own entity.
Rich Snippets Spam Report Tells Google About Manipulated Structured Data
Use the rich snippets spam report form to inform Google about instances of manipulated structured data.
Valid Structured Markup Is Not Necessarily Sufficient for Rich Results
Rich results won’t necessarily appear just because Google’s testing tools say that the structured markup on that page is valid. John recommends reading the relevant developer documents to find out about other requirements for specific rich results.
Google More Cautious Displaying Rich Results When Unsure About Structured Data Implementation
Google has algorithms which decide when it makes sense to display structured data as rich results. If Google is unsure about a website or the way structured data has been implemented, then it will be more cautious in displaying structured data as rich results.
Provide Last Modified Date in Content & Structured Data For Rich Snippet
Providing the last modified date within the page’s content and as structured data makes it easier for Google to show this as a rich snippet in the SERPS, especially if both dates match.
Google Displays Different Date Types Depending on Which is Most Relevant
Google’s algorithms decide to show the last modification date or the original publication date depending on which is deemed more relevant. For example, the last modification date might be more useful if something has significantly changed on the page.
Rich Results Won’t Always be Shown in the Search Results
Pages will sometimes have a variety of markup and rich results available which would be visually overwhelming, so Google will select which rich result to show from a site depending on the query e.g. a video result for one and a review for another.
Rich Snippets Will Better Match Page Content on Mobile After Mobile-first indexing
John suspects the most visible impact of mobile-first indexing on the search results will be that rich snippets will better match the content seen on the page for mobile devices.