I doubt FB could replicate this. Fb itself is a non-starter the people who use this app haven't been on Fb in years. Okay, so Instagram. If they could, they would’ve.
I think there are problems with making Instagram seem tacky by clobbering on a marketplace. It would make it look cheap and shilly. Right now it’s the most rarified space to share pictures of your awesome lifestyle. I think you can either have that very cool, chic vibe or the amazon marketplace vibe.
I think that despite their enormous resources, there are places that brands can’t go.