Yes. Pick up a Vogue. A fat magazine with virtually no content but a lot of pictures. A mixture of advertising and photo shoots. There is a whole, massive demographic out there that just loves this stuff, and isn't technical at all.

The existence of vogue shows that there is a demographic who likes to flip through nice pictures. Sometimes they dog-ear the pictures to come back later and look again. People like to leave the magazine lying around their place as a social indicator that they are interested in fashion, and they like to mark which bits of that fashion they're interested in. That's pinterest in a nutshell.

Now go to any magazine rack. There are are broad range of these niches. It's not about replicating a magazine, it's about understanding what purpose that magazine exists for. Is it interesting articles? Wanted ads? Industry information? The purpose and niche of the information is what people want. These all can be more innovatively delivered and shared than a glossy magazine dropped on a doorstep.

Even faster and perhaps more instructive is looking up Bethany Mota:

"Her YouTube channel has more subscribers than Lady Gaga (4.8 million), she has more Instagram followers than Elle, Vogue, Glamour and Marie Claire combined (2.2 million)."

(First read about her yesterday, accidentally. Yeah.)

    virtually no content but a lot of pictures

this is ridiculous to say. photos are content.

Try telling that to the Google Adsense compliance department...

Well, exactly. That shows the difference in understanding.

It's basically a "lookbook" concept, which is something you flip through for inspiration and to see what the current trends are. If you want a technical parallel, think Dribbble.

Pinterest takes this and adds a mix of dynamic wishlists and storefronts to it - with alerts of price drops, and conceivably price and currency calculation for an international audience down the line.

I generally hate the term, but Pinterest also acts as a more curated lookbook, since you can choose whom you follow to compose your own magazine-like feed.

I don't mean to give the impression that I have any idea about the profitability of Pinterest, because they are hauling a truckload of static content - on Django, to boot.

You mean a mood-board; which is used to communicate a visual style. A lookbook is usually to give an overview of a single brand's season.

It is used extensively in all visual creative industries, like interior decoration, architecture and of course fashion and photography.

It's actually often one of the main deliverables early on in projects and thus also an important sales document (i.e. serious money is won or lost on the quality of the mood-board.)

How are they hauling static content on Django? Any reference for that?

I thought everyone is using sendfile/x-accel and wrap CDN with static contents these days.