One SEO professional was concerned about Schema, namely, shop ratings. They wanted to know whether Google prefers product ratings or shop ratings for an e-commerce site.
Additionally, their other question was: would Google show shop ratings on category pages?
John answered that for shop ratings, Google does not try to show them if they’re on the shop themselves.
He explained in this fashion: if you have a directory of local businesses, putting ratings on those local businesses is just fine and to be expected.
However, placing a rating on your own website is not considered an objective rating.
Think of it this way: reviewing and rating someone else’s website on your own accord is an objective rating. But, reviewing your own website is not an objective rating and would be considered biased.
Because of this, reviewing your own website is not something that Google would want to show in their search results because there’s no way for that to be entirely accurate or objective.
However, if you have an e-commerce site, then John recommends using product ratings, because the individual products can then be reviewed by yourself.
In addition, you can also specify that these products are something that were reviewed by yourself.
If you’re really just a directory of e-commerce sites, this situation would lend itself well to having ratings on individual websites.
This happens at approximately the 34:32 mark in the video.