People often talk (and write) about how commercialization is changing the nature of microfinance. Yet increasingly it looks like an even more fundamental shift is afoot. Microfinanciers are finally figuring out what their customers want.

The well-worn story of microfinance goes something like this. Lend a poor person in a poor country a little bit of money, and that person can invest in a business—by buying a sewing machine, say, or another cow. Over the long run, that person pulls himself out of poverty with the income generated by his endeavor.

One reason this story involves a loan is because in most countries it’s a whole lot easier to lend money than it is to take deposits. (The latter requires a banking license, which the former doesn’t.) But there’s another reason loan-making is at the center of traditional microfinance: the people who started this work more than 30 years ago assumed that since mainstream banks didn’t lend to poor people, there was a massive, untapped demand for borrowing.

The thing is, no one ever really asked poor people if business loans were the most important financial product they were missing. That’s now starting to change, thanks in part to a recent wave of academic research. As it turns out, poor people lead complicated financial lives and they need money for all sorts of things.

Thursday I was at this conference, where Dean Karlan of Yale talked about research he’s been doing with Jonathan Zinman of Dartmouth. In interviews with microfinance recipients in the Philippines, the pair discovered that some 46% of borrowers used a decent chunk of their business loan to pay down other debt and about 28% spent part of the money on a big household purchase—even though fewer than 4% of people in either category ever admitted this to their bank. (Disclosure: I was at this conference because I am now doing work for the Financial Access Initiative, which co-sponsored the event.)

This sort of finding—which quantifies what many practitioners have long suspected was the case—is having an impact on how microfinanciers go about their business. “We’re an industry built on assumptions, and we’ve gotten to a point where we have to test those,” said Carlos Danel, a co-founder of the Mexican microfinance behemoth Banco Compartamos. ”Research is showing us that we actually don’t know a lot about the customers we serve.” That’s why Compartamos is conducting a 4-year study with Karlan and other researchers to find out how customers use microfinance products, and how those products do—or don’t—change their lives.

As Danel put it, microfinance is an industry that was born out of supply—one that came from people thinking about what organizations were capable of doing. Now, he said, the challenge is to figure out what poor people around the world actually need.