Last week Samford University sent a round of acceptances to applicants, and soon each of them will receive an invitation to join the Class of 2017′s Facebook group. Students who do so will be able to make friends, form social groups, and ask questions about the Alabama university. Meanwhile, Samford’s admissions office will get data that can help them predict—and shape—enrollment outcomes.

For the last two years, Samford has used Schools App, an application for Facebook and mobile devices that was created by Inigral, a technology company. This week Inigral unveiled an enhancement called “enrollment intelligence,” an algorithm that links social media with predictive modeling. By analyzing the “social and behavioral data patterns” of students who use the app, the company can tell participating colleges “who’s likely to enroll, who’s on the fence, and who’s not likely to enroll,” says Jamie Glenn, the company’s chief executive.

The app allows colleges to track the number of friends each student makes online, and the number of messages he or she writes. The more active the student, the more likely he or she is to matriculate. Still, even users who don’t participate in discussions (“chronic voyeurs”) provide colleges with an indication of their interest; admissions officers can use the app to track how many times each student logs in and what content he or she clicks on. (Students are told upfront how the data are used, and by whom, Mr. Glenn says.)

Brian L. Kennedy, assistant director of communications in Samford’s admissions office, says the service has helped the university reach out to prospective students who are the best bets, as well as those who might not be. “We want to engage people who are engaging with us, who are super-plugged in, who really want Samford,” he says. ”Those who aren’t super-active on the app, we see if they’re active in other ways.”

In turn, the admissions staff can use the app to measure whether a student becomes more interested in Samford over time. “We put a lot of effort into getting students to join the app,” Mr. Kennedy says. After all, joining is a strong demonstration of interest. For this year’s freshman class, Samford’s deposit rate was 32 percent, but it was 66 percent for those who subscribed to the app (and 13 percent for those who did not).

So far, more than 100 colleges are using Schools App. Its brand-new feature is another reminder that demographic information (who students are) is only part of the enrollment story; what more and more colleges want to know is, what are our applicants doing?

In case you missed it, be sure to check out my colleague Marc Parry’s excellent article on how colleges are using “Big Data” to serve students.