Business writers frequently distill the habits of wildly successful companies into formulas for others to imitate. A persistent methodological problem undermines much of this literature. By studying only firms that succeeded, analysts cannot know whether the traits they identify, such as bold risk-taking or relentless focus, actually caused success, since countless failed firms may have shared the very same traits. The failures, having vanished, never enter the sample. A trait common to winners and losers alike explains nothing about why the winners won. Distinguishing genuine causes from mere correlates would require examining the full population of firms that once pursued a given strategy, not just the survivors whose stories happen to be told. Absent that comparison, the confident lessons drawn from success stories remain, at best, untested hypotheses.