I think it might be fairer to look at AMZN's price to revenue ratio and compare that with other big companies which have margins AMZN might reasonably have when they start trying to make profits. That would maybe give a reasonable understanding of expected upside. Looking at their profits when they aren't trying to make a profit is a little silly.

GOOG on the other hand I think is a fair enough comparison. Actually GOOG has pretty much failed at all their attempts to make money off anything but ads, which I consider kind of worrying.

PS FYI you posted this twice and the other one is marked dead. I recommend deleting it.