Yelp…is…essentially a poster-child for semantic markup. This spring, Google’s introduction of rich snippets has allowed Yelp’s listings in the SERPs to stand out more, attracting consumers to click more due to the “bling” decorating the listings in the form of the star ratings.
There are now some very good reasons why sites with ratings and reviews should be adopting microformats, and it’s not that hard to do! For a more detailed explanation, read my recap on the subject, Why Use Microformats?