This is the ranking boost mentioned: http://i.imgur.com/KsSmYH8.png
"Top stories" relevant to the search are shown, even if they’d otherwise be on page 10 or worse of the actual search.
Any AMP page can end up there, but only AMP pages. This is a ranking boost.
Original article was about e-commerce. The Top Stories carousel is not relevant to e-commerce since it only contains news articles.
It ranks at #2. With articles that otherwise end up at #14 (just checked).
That’s a 12 place ranking boost. You can’t get that anywhere else.
> Original article was about e-commerce.
You’re competing with ebay, and ebay uses AMP on all pages so that they get the #1 spot with the carousel.