There is a revolution happening beneath the surface of the eCommerce industry on Facebook right now.  You can detect it with a lot of their Shopping, Marketplace, Checkout, Augmented Reality (AR) focus.

Facebook is building out a unique vision that:

• is unique to its own strengths (fashion, brands)

• is where people already are (sharing, friends)

• is innovative (I think they have a chance to really advance the bar in AR/VR-based shopping).

• is focused on the front-end experience over the back-end.

So much that in 5 years, if Amazon continues to stand still in these areas, Amazon more and more turns into the "next Walmart" (i.e., grocery, replenishes, consumables), leaving Facebook in a prime position to own some of the most exciting parts of eCommerce - fashion, luxury, and beauty.