I have a site that essentially has two types of pages. First, I have a home page (http://whatgoeswiththis.co) that shows a stream of products. Then, I have a detail page (for instance, http://whatgoeswiththis.co/item/6531) that is unique to each product. I include structured data on this page for schema.org/Product and /Offer.
Should I also markup the product as a schema.org/Product when it appears on homepage as part of a feed, even though this homepage is constantly changing?
Similarly, should I markup a person as a schema.org/Person every time they make a post or comment and their avatar/name shows up, or just once on their profile page?