"Designers always complain that though they build beautiful collections, their best pieces never see production because retail buyers don't see a market for them," says Aslaug Magnusdottir. The former fashion consultant and investor was VP of products and services at flash-sale site Gilt Groupe when she got to thinking: If a designer wants to sell, why give the retailer all the control? Last year, she launched a site to let shoppers preorder pieces right after runway shows, six months before they may hit the floor of, say, Barneys. "No one thought anyone would purchase luxury items online, but we help our customers feel comfortable by offering style advice through editorial content and personal stylists," she says. It works: 250 designers now offer their wares, and the average purchase is $1,400. When you have that kind of money to spend right now, why wait?