There was a time when the browser you used was nothing more than a matter of taste or subtle self-expression. Safari was for Apple purists, Chrome for the fleet of foot, Firefox for the universally compatible, and Internet Explorer for the masochistic. But in the end, they all ended up doing more or less the same thing, just with marginally different visual styles and at marginally different speeds.

But in the world of Big Data, everything means something. Cornerstone OnDemand, a company that sells software that helps employers recruit and retain workers, analyzed data on about 50,000 people who took its 45-minute online job assessment (which is like a thorough personality test) and then were successfully hired at a firm using its software. These candidates ended up working customer-service and sales jobs for companies in industries such as telecommunications, retail, and hospitality.

Cornerstone’s researchers found that people who took the test on a non-default browser, such as Firefox or Chrome, ended up staying at their jobs about 15 percent longer than those who stuck with Safari or Internet Explorer. They performed better on the job as well. (These statistics were roughly the same for both Mac and PC users.)

The Percentage of Employees Who Stayed at a Company, by Browser, Over Time

Cornerstone OnDemand

Michael Housman, the chief analytics officer at Cornerstone, said that while the company’s research hasn’t identified anything to suggest causality, he does have a theory as to why this correlation exists. “I think that the fact that you took the time to install Firefox on your computer shows us something about you. It shows that you’re someone who is an informed consumer,” he told Freakonomics Radio. “You’ve made an active choice to do something that wasn’t default.”

Why would a company care about something so seemingly trivial as the browser a candidate chooses to use? Call centers are estimated to suffer from a turnover rate of about 45 percent annually, and it can cost thousands of dollars to hire new employees. Because of that, companies are eager to find any proxy for talent and dedication that they can.

That said, Housman notes that browser choice isn’t something that Cornerstone’s clients consider when hiring—that’d be seen as too intrusive. They do, however, track other variables that correlate with high rates of employee retention. Giving employees raises can help, but their positive effects dissolve after about a month. More important is getting along with one's boss, which is more responsible for getting people to stick around than all of the other variables combined.

As correlations like “Chrome users are better employees” bob up from a sea of data, it’s important that they don’t start to generate the same rigid biases that Big Data is partially dampening—rejecting an applicant with the “wrong” browser would be silly. But still, some correlations deserve swift and immediate judgment: Housman also told me that his data set revealed that people who use “boozy” or “sexy” in their email addresses make for worse employees. But we didn't need Big Data to figure that out.