It’s the latest social media craze. Pinterest is about visual images, where most are about words, and it’s grabbing a growing market of users who want to show off on the web. It seems as if it has no plans for making money, just a blind optimism that fun and technology will succeed where others have failed. But Pinterest may have a secret.

Pinterest has really taken off because it’s quick, easy and attractive. “The simple and highly visual site lets users save—or “pin”— coveted outfits, recipes, home décor ideas and do-it-yourself projects on virtual bulletin boards, for their own use and to share with others,” says NPR’s All Tech Considered. “Beyond its visual appeal, another thing quickly stands out on a first visit to Pinterest: a somewhat feminine orientation. The opening page is wallpapered with images of women’s outfits, DIY craft projects, recipes and wedding dresses. According to various reports,  58%   to 97% of  Pinterest users are female.”

“The site is totally fun and addictive,” says Jura Koncius of the Washington Post. “Why is this so entertaining? It’s like curating your own magazine or pretending you are picking out stacks of Tiffany diamonds for yourself. (See my Jewels bulletin board.) It’s sharing the closet and kitchen pantry of your dreams. It’s an online filing system that won’t take up space in your den.”

But, she notes: “It’s also why marketers are flocking to the site. It’s becoming a huge source of traffic to online stores thanks to those who decide to make the dream pinboards a very real purchase.”

It’s growing like a weed, despite the fact that it’s currently still invite-only. “Traffic to the website… has grown tenfold over the past six months,” says Business Insider. “In January, the number of visitors on Pinterest.com was almost a third of that on Twitter.com…. According to a recent study. It currently drives more referral traffic thanYouTube, Reddit, Google+ and LinkedIn.” Referral traffic is people that go to other sites to buy stuff they have seen on Pinterest.

Is this the future of retail? Previous dreams have failed to materialize. Retailers are shuttering virtual stores on Facebook as F-commerce fails to materialize, says Jeff Bercovici at Forbes. But, he points out: “Just as retailers are losing faith in Facebook as platform for e-commerce, it seems, they’re warming up to Pinterest…. Pinterest shows that if your business is selling stuff, a social network of stuff beats a social network of people.”

And what are their plans for making money? Gulp. They don’t have any. “Pinterest’s monetization strategy isn’t in the oven and it’s not even off the baking table,” said Jeremy Levine, a board member of Pinterest and a venture capitalist at Bessemer Venture Partners, to the Wall Street Journal. “We have one hundred ideas but no execution as of yet.”

As the WSJ points out, “Pinterest’s situation isn’t unusual for an Internet start-up; some may even call it cliché. After watching the growth of Facebook Inc. and Twitter—both of which grew quickly at first without having a business model—Pinterest co-founder Ben Silbermann said he is following the same path and will worry about details later.” It’s not so much “if you build it, they will come”—more the other way around: first get an audience, and then find a business model.

Except that all of this arouses our suspicion, and fortunately one or two other writers agree. “Now, all of this is pretty standard Silicon Valley speak,” says Alexis Madrigal at the Atlantic. “They pretend that they don’t care about making money off of users and we users pretend that we aren’t the product. It’s all about “building value” and “creating a better experience” and all that. Which is fine and good. I find the Valley’s deep and starry-eyed belief that money flows to all the right people to be very endearing. But let’s get real here.

“The key to this model here is the Superman III principle: they are making pennies on a retail shopping market that is truly gigantic, and they are taking their cut from the top-line…. And really, what a win for everyone. Users get a great service and don’t have to look at advertising. Retailers get a new outlet for marketing. Pinterest connects all these buyers and sellers.” 

Why are they shy about talking about money? The site hit a small hitch recently when it was discovered that the company was adding its own affiliate marketing code to links, so that it could make some cash on referrals. The company quickly announced that it no longer used this method, and that it was looking for other ideas. First, it will have turned off some customers, and at the moment, growth is the priority. Second, they probably want to own the way they make money—not use an external company like the one they were trying out.

So does any of this make Pinterest less fun? No. For now, it’s a great new playground for those with a good visual sense who like “curating” their own images. One day, that playground might make some money for someone—but for now, it’s all about play.