maniacmika: Indeed.
I was wondering if I really do not have Doom 3 yet, as I remember seeing it in my library.
Turns out, Amazon Doom 3 is not the same product as Doom 3, but it includes it. (See picture)
I remember something similarly weird with Fallout and Fallout Classic.
Must be my case too, can't remember where I got it from.
But nowhere in the description of the product, Doom 3 or BFG ed. does it say it came from a third party. I do remember that Amazon Prime games come with a "(Amazon)" (or something similar) at the end of the title when you add them but that's the only time you see it.
"View store page" leads you to the normal store page and tries to sell you the game that led you there, no mention of special give-a-way editions or a discounted upgrade to a license for a game you already own... weird for a store that prides itself in being "DRM done right".