Founded as a way to take correspondences you receive in your mailbox and convert them into digital pieces of work, Outbox eventually serviced more than 2,000 customers from across the United States, with 25,000 on the waiting list. It wound up scanning more than 1.5 million pages and delivered over 250,000 requested mail packages. Unfortunately while the traction is impressive, things apparently weren’t that prosperous internally. The company’s co-founders write that its marketing efforts were unsuccessful. Specifically, they cite that an effort to onboard the 4,000 individuals on its San Francisco waitlist led to an email marketing campaign that resulted in a yield of under 10 percent. Additionally, Outbox saw its user acquisition costs be more than $50 per lead. Besides its marketing efforts, the service says that its “density numbers” remained “consistently flat” causing it to spend more than it projected. The realization soon hit Outbox that its operation deficit was too high and that its situation was too far out of its control to change. But not one to leave off any lessons learned, the founders did spell out several things they took away from their experience: Photo credit: SAUL LOEB/AFP/Getty Images