Members can use images they like from the Web or from other Pinterest profiles, categorize them in genres and share them with other Pinterest users. Those who click on the images are often able to locate the website they originated on. Members can also comment on those pictures.
As the site has grown in popularity, so has interest from firms that see it as a chance to boost brand awareness.
"Businesses are definitely taking notice," says Andrew Lipsman, analyst at research firm ComScore.
Pinterest's large user base — and ease of use — is appealing to mom-and-pop retailers and corporate giants alike, he says. It had 11.7 million unique visitors in January, vs. 1 million in July.
The start-up's users, who are mostly female, are also highly engaged, Lipsman says. In January the average visitor spent 98 minutes on the site, up from 38 minutes in July.
Big companies, such as high-end retailer Bergdorf Goodman, use the site to display images such as swanky spring shoes.
Smaller firms also use it to promote their goods and services. California restaurant chain Tender Greens showcases images of its chefs at work, as well as food served through its catering services.
Tampa-based wedding planner and blogger Lauren Grove uses Pinterest to showcase items that would appeal to brides, as well as to draw traffic back to her ad-supported website. Pinterest also lets members collaborate on bulletin boards, and Grove has used that service to share ideas with her bridal clients, especially those she can't regularly meet with face-to-face.
And while firms often display images of products that relate to their core business, many also post pictures that aren't directly related. West Elm home goods company, for instance, has images of an unusual striped wedding tent and overflowing bowls of white baking flour on its Pinterest page.
That diversity is smart, Lipsman says.
"You don't want to be seen as inauthentic and seen as just pushing your product," he says.
While it's simple for firms to create their own pin boards on pinterest.com, Lipsman says businesses can make their products even more Pinterest-friendly by adding "Pin It" buttons to their websites. So if a user sees a photo she likes online, it takes a simple click to add it to her personal site.
Furniture retailer Raymour & Flanigan has even added a Pinterest icon to e-mails that it sends to potential customers.
Those who click on the the red-and-white "P" icon are taken to its Pinterest page, which features images of "new products" from the retailer, as well as aspirational photos of "lovely living rooms" and "beautiful bedrooms."
Tender Greens co-owner Erik Oberholtzer says that Pinterest isn't just for reaching out to potential patrons. He also uses it to gather inspiration on what meals to serve, how to display food and what art would look good in restaurants.
"It's not only about what we are sharing," he says. "It gives us access to find people and organizations that can turn us on to ideas that otherwise we might not have considered."