Social media sites such as Facebook, TikTok, and Instagram have given many organizations a new hiring tool. According to a 2018 CareerBuilder survey, 70% of employers check out applicants’ profiles as part of their screening process, and 54% have rejected applicants because of what they found. Social media sites offer a free, easily accessed portrait of what a candidate is really like, yielding a clearer idea of whether that person will succeed on the job—or so the theory goes.

A version of this article appeared in the September–October 2021 issue of Harvard Business Review.