How to Add Aggregated Reviews to Your Knowledge Panel

Google has just launched Reviews from the web globally on both desktop and mobile, a feature that allows you to have aggregated user ratings (from up to three review sites) within your Local Knowledge Panel information. Here's how Google explained it:

By implementing review snippet markup and meeting our criteria, your site’s user-generated composite ratings will be eligible for inclusion. Add the Local Business markup to help Google match reviews to the right review subject and help grow your site’s coverage. For more information on the guidelines for the Reviews from the web, critic review and top places lists features, check out our developer site.