|Why They're Hot:
E-retailer Skinny Ties was an early adopter of responsive design, aiming to better serve its increasingly mobile customers. Responsive design enables developers to create a single web site that adapts to the size of the device the shopper is using. On a PC the home page shows nine ties across, but on a phone it only shows three, with arrows that let the shopper see more. Since launching its responsive site in late 2012, sales through desktops have jumped 99%, tablets 190% and smartphones 231%. "The big way we did this was thinking mobile-first," says Brendan Falkowski, head of information technology. "Instead of planning the look of a site on a big screen, where you have a lot of space to move things around, we looked at content on the small screen first, where you don't have that freedom."