In 2010, software engineer Natalie Gordon was pregnant– and fed up with the overwhelming baby aisles in big box stores. So she quit her computer job to code the registry she wished existed. No pink-and-blue giraffes. No allegiance to a single store. Just a universal list that let friends give the real help that new parents need—from strollers to diaper services to dog-walking. Natalie coded the first lines of Babylist during her son’s nap time. She managed customer support, pitched bloggers from coffee shops, and learned growth the hard way—first through affiliates, then with a pivotal P...