You’re proud of your startup. From conception to birth, you’ve doted on it. Now, it’s growing and providing tons of data for you to examine. Like a beaming parent, you explore the information eagerly, pleased at your company’s progress. But beware the blind spot all moms and dads face: Your apparent success might not be all that successful.

Entrepreneurs look at facts and figures far differently from investors and board members; consequently, they often overlook or misunderstand the growth metrics at their fingertips. As with anything in life, they must see the company’s data with open and accepting eyes.

Some growth metrics will highlight success; others will cast shadows of doubt. A founder’s job is as much a leader as an interpreter for ...