Rich Snippets are a way to provide Google detailed product information in a structured way so that in search results it can display rich snippets (for example, price, availability, and review ratings)
Sample:

Rich snippets help you to:
Attract potential buyers while they are searching for items to buy on Google.
Submit your product listings for free.
Control your product information. You can maintain the accuracy and freshness of your product information, so your customers find the relevant, current items they're looking for.
Because this is a vQmod, no core files are touched, and the changes should carry over to the next version.
Extension page: http://www.opencart.com/index.php?route ... on_id=6536