Even if you haven’t ever visited popular visual bookmarking site Pinterest, you might recognize its design elements—which have been popping up everywhere since the startup burst onto the mainstream scene in 2011. The site doesn’t use traditional Web building blocks. “It’s almost like a window-shopping mode,” says Khoi Vinh, the former design director for NYTimes.com. “It puts the ball back in the user’s court,” muses Andrew Beck, a Web designer at Blue Fountain Media. “It flattens the information hierarchy,” describes Jeff Croft, a Web designer and co-founder of eBook lending site Lendle.