FORTUNE — Photos are having a moment. Companies such as Instagram, Pinterest and Tumblr, the big three image-based platforms on the Internet, seem to be reaching new milestones every week. Facebook bought Instagram for a whopping $1 billion, and the newly public company may be purchasing Face.com, which provides software that recognizes, well, faces. Meanwhile, virtual inspiration board Pinterest’s valuation skyrocketed to $1.5 billion and microblogging site Tumblr recently broke into comScore’s top 50 web properties with 23.5 million unique visitors.
Brands have taken notice.
Unlike the slow uptake by marketers of other new technologies — from early television advertising to social media — companies have jumped on this bandwagon quickly. Companies are creating Pinterest boards and Instagram accounts, hoping high-quality images will grab customers’ attention and, hopefully, encourage them to buy offline. “Visual storytelling is essential to building a strong online identity,” says Michael Bepko, global online community manager of Whole Foods (WFM), which started using Pinterest in July 2011. “ I think it allows us to tell a story – through posters, through banners, through text – we can get particular messages across through image sharing…in a very instantaneous way.”
It’s also following one of the first rules in business: go to where your audience is. “Ubiquitous camera phones and connected mobile devices has exponentially boosted social sharing of digital images,” says Nate Warner, Red Bull’s digital marketing director. “We saw a constant stream of people sharing their own images from our events as well as images pulled from [our] properties, or re-sharing images from Red Bull’s social media accounts,” he continues. “The ongoing growth validates this type of positive connection our fans feel with the brand.” Red Bull – one of the first and more popular brands on Instagram — has more than 230,000 followers and more than 87,000 user-submitted images tagged #redbull on the app.
One could argue that Tumblr started this relatively recent need for image-driven social connection between brands and their customers. Companies have flocked to the microblogging site to share behind-the-scenes photos that followers are only too eager to reblog thousands of times. With each repost, a user firmly aligns themselves not only with the brand, but the aesthetic being pushed through their curated images. The 2,275 people who interacted with a vintage photo of 50s era beach combers on Kate Spade’s Tumblr are collectively saying they get how the bygone look inspires the brand’s quirky prep creations today.
For some brands, having a presence on these platforms is just as necessary as having a Facebook page. “As a lifestyle brand you can’t not be on Pinterest right now,” says Vanessa Holden, creative director of West Elm. “It’s a bustling, incredibly vibrant place of inspiration and sharing around design, cooking, entertaining, crafting, making, you name it. Pinterest really enables us to have a visual conversation with our community.” Relative ease of use has been a big boost, says Alex Wheeler, vice president of global digital marketing at Starbucks (SBUX). “The beauty of that platform is its elegance and simplicity.” It allows Starbucks and its fans to show “shared values and product experiences that are very personal around life moments,” Wheeler says.
Some brand’s Pinterest and Instagram (FB) sites are a combination of brand-created and user-curated images — and that is creating a kind of brand ing that exists outside of the typical indenties. In the case of an American Airlines social photo campaign, travelers could submit pictures from their trips based on a single theme each week. “The visual images associated with the themes provided a more compelling call to action and structure for consumers to create on behalf of the brand versus a standard promotional call to action,” says Tom Edwards, vice president of digital strategy at The Marketing Arm, which worked on the campaign. “Via compelling images, brands enable consumers to drive the creation of branded content, which drives additional attention in a user’s social activity stream, thus driving additional consideration for the brand.”
But does 617,994 photos tagged #starbucks on Instagram equal more people coming in for Frappucinnos (which, by the way, is tagged 16,782 times)? The answer is still unclear. Wheeler of Starbucks says the company is focused on using the medium to get into customers’ conversations. And Whole Foods’ Michael Bepko told Fortune that “between December of 2011 and March of 2012 we saw a 337% increase in traffic referral from Pinterest to Wholefoodsmarket.com.” With metrics like those, brands are betting sales can’t be far off.