Gilt Groupe took only four years (mostly during a recession) to take the fashionista crowd by storm, revolutionize both the fashion and e-commerce industries, attract five million members and earn a $1 billion valuation. But it’s a steep climb to become an “overnight” success.

BY INVITATION ONLY: How We Built Gilt and Changed How Millions of People Shop (Portfolio; April 12, 2012) by Alexis Maybank and Alexandra Wilkis Wilson is a remarkably human story of two best friends who risked everything to cofound a startup that catered to their own passions as shoppers and grew beyond their wildest dreams.

When Alexis and Alexandra started Gilt Groupe in November, 2007, fashion had yet to leverage the unique capabilities of the Internet, and e-commerce sites usually just displayed their wares without any inventiveness. Their shared passion for shopping at New York sample sales made them wonder if they could bring to the Internet the excitement of scavenging the bins for a bargain at an exclusive sample sale. Bingo! They launched their members-only website to a select national group of thirteen thousand young, high-end shoppers. They offered 50–70 percent off luxury brands like Marc Jacobs and Valentino, in “flash” sales that would start at noon and last just thirty-six hours. It soon went viral as members rapidly invited friends to join and competed to win a bargain with the same fervor as if they were playing a hit online game.

But while there is much to learn from this smart business model, the evolution of their idea to successful business is even more illuminating and thrilling. Starting with a friendship forged at Harvard Business School, the authors weave an engaging narrative that takes readers from their jobs at eBay and Louis Vuitton, to trips to Brazil and Japan, to weddings and velvet rope movie premieres. Along the way they encounter a variety of celebrities, personalities and business leaders from Madonna and Gwyneth Paltrow, to Meg Whitman and Jeff Skoll, and from Zac Posen to Mickey Drexler and from Christian Louboutin to Valentino. They also share the less glamorous but adrenaline rush side of starting a business including such nail-biting decisions as: How to choose the right name for a company? How can I ask my friend to risk her career—and our friendship--to take an uncertain chance with me on a startup? How can we convince brands to discount their luxury goods without hurting their brand? How can we avoid getting overwhelmed by rapid growth? How can we make being women an advantage

Full of hard-won insights, BY INVITATION ONLY is an exclusive invitation from the authors to read and be inspired by their wild ride of launching a hyper-growth startup.