SunFrog Shirts isn’t concerned with building a brand; it just wants to make a quick sale.

The approach has served the company well since its 2012 founding. “We figure that about 1% of the U.S. population owns a SunFrog shirt, but almost no one knows who we are,” says Josh Kent, CEO of the web-only novelty T-shirt retailer, which sold an Internet Retailer-estimated $12 million worth of T-shirts online in 2014.

Social media, and Facebook ads in particular, play a part in roughly 85% of SunFrog’s sales, Kent says. Nearly a quarter of consumers, 24.1%, arrive at the online-only novelty T-shirt retailer directly from social networks, according to the forthcoming Social Media 500, which ranks retailers by the percentage of their site traffic that stems from social networks. Most of those clicks stem from Facebook display ads that appear on the right-hand side of desktop users’ screens or the boards that affiliates create on Pinterest. And that figure does not include consumers who may have seen a SunFrog ad on Facebook earlier, went elsewhere on the web, and later went to the SunFrog site.

The strong social traffic reflects the SunFrog business model, which relies almost exclusively on affiliates buying Facebook ads to drive traffic to SunFrog’s site. The approach, Kent says, acknowledges the new marketing reality for retailers like SunFrog: Advertising on social media—and Facebook, in particular—is easier and more effective than paid search for a brand focused on driving impulse buys. “The days of hoping that someone searches a specific keyword and bringing them over to our site are over,” he says. “It’s a different world.”

Rather than hope that a consumer who searches “pug” in Google might decide to buy an “I hug pugs” T-shirt, the retailer’s affiliates use Facebook’s targeting features to show ads to women between the ages of 18 and 24 in California who like the pug breed page or have indicated they plan to attend a Facebook-organized “Southern California Pug Meetup.”

The approach is simple and cost-efficient, Kent says. “If you love pugs, we’ll pitch you a pug shirt because you let Facebook know that you like pugs,” he says. “This isn’t the typical e-commerce sales funnel; the funnel is defined by finding the targeting that drives someone to click and buy.”

SunFrog is No. 729 in the Internet Retailer 2015 Second 500 Guide.