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Will Sacks did not plan to go into the menstruation business. When he travelled from Toronto to Reno to attend his first Burning Man festival in August 2009, he only knew that he needed a change. At the age of 29, he was having a personal crisis. "I had forgotten that I wanted to be an entrepreneur," he told me earlier this year. "I had forgotten that I wanted to create a company that could put a dent in the universe." He quit his job as an energy efficiency consultant, shut down the small online business he had been running on the side, and booked a plane ticket to the desert.

Before beginning the drive to Burning Man from Reno airport, Sacks posted a message on Craigslist offering a ride in his rental car to anyone who needed one. A young woman named Kati Bicknell answered. Petite and pale, with thick brown hair, Bicknell looks like she stepped out of a pre"Raphaelite painting. She exudes an intense, slightly mischievous, energy. Sacks comes across as calmer. He locks eyes when he talks to you, pausing every few sentences to check in: are you still with him? Does his optimism sound naive?