How to mark up the rating stars of list pages?
The "Customer Ratings and Reviews Pro + Google Rich Snippets" module allows you to mark up your product ratings on your product list pages (like category page, brand page, etc...).
Follow the following procedure to introduce rating rich snippets on list pages:
First, you have to check if the products in your product list pages are already marked up by your theme. According to this, you will be able to configure the module correctly. Indeed, the product rating markup requires beforehand the markup of the products.
Go to one of your shop product list pages, like for exemple a category page. Right click on one of the products of the list and select "Inspect". Look for the string:
Here is an example:
If you find this string then it means the products are already marked up by your theme. You will not need to ask the module to do it.
In the module configuration go to the "Reviews" section and click the "Stars in list pages" tab. For the "Display rich snippets rating" " option select "YES":
A second option appears asking you if you have rich snippets "porduct" in your product-list.tpl. If previously you have noted that your theme already marks up the products on your product list pages (presence of the string: itemscope itemtype="https://schema.org/Product"), select "YES":
If not, you have to ask the module to make the markup of the products on list pages before marking up the ratings. So, select "NO":
It is important to have previously checked that your theme doesn't already make the markup, because if you select "NO" and that in fact your theme already introduces rich snippets for products, then Google will consider the product ratings as "products" in their own right and may not do the matching...