Google is now asking me for the addition of microdata elements that I couldn't possibly posess unless I actually held my own stock.
I'm an affiliate who runs Amazon websites.
Global identifier (gtin8, mpn or similar): What to fill out?
Brand: I suppose I could fill that out by doing a manual pass over all my product reviews to provide it.
Description: Same as brand.
Sku: What to fill out here? I just put in the ASIN.
Aggregate rating: This only applies to multiple product reviews of the same product. Ergo: this only applies if you own your own inventory. My review count is always 1 and the aggregate gets the same score as my regular review element does.
Offers: This one is downright impossible. Availability? Item condition? Price? Price valid until? This info is not easily accessible from Amazon. The availability and condition have pre-defined, valid values available, none of which apply to an affiliate running an Amazon site.
But search console still generates warnings for this stuff.
I've tried to provide the most microdata elements with the most sensible values that I could think of. But the 'offers' element is just downright impossible.
Looks like you're gonna be stuck with impossible-to-solve warnings in your search console from now on.
You'd think affiliates would also be able to use this structured data. Guess google doesn't like us much.