How a Subscription-Box Founder Is Using Data to Survive -- and Thrive With Rockets of Awesome, Rachel Blumenthal has built a data-driven supply chain to make her business faster and smarter.

Kids are picky and grow constantly. As a parent of two, Rachel Blumenthal knows that well. "Every season, my kids had outgrown the previous season's clothes, and I was replacing complete wardrobes," she says. "It was time-consuming and expensive and, frankly, not much fun."

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Blumenthal wanted to fix her own problem. She'd previously founded online baby registry Cricket's Circle, so she knew the world of parenting ecommerce. But as she thought about kids' clothes, she began drifting toward what seemed like a troublesome solution: a subscription box service. It's a model that many other startups, selling many other wares, have tried and failed at. It's hard to line up vendors, difficult to keep subscribers for long and nearly impossible to anticipate demand.