Facebook Creative Labs released numerous standalone apps. Often, the best parts of those apps were infused into the main Facebook app. In many cases, though, the apps themselves disappeared. Inspirit co-founder Julie Zhou, who scaled the Facebook app from 8 million to over 2 billion users as the company’s VP of design and research, explains the logic behind this failure rate. Rather than letting underperforming apps linger, Facebook set clear goals for the apps and generally retired them after a year if they didn’t meet the rigorous benchmarks.