Supper, in this case, came in the form of Merge Healthcare, a company whose software processes and stores medical images like X-rays and CT scans, and which IBM swallowed up for $1 billion. That followed several feedings in the spring—when Big Blue bought a company called Explorys, which had amassed a staggeringly large data set from millions of medical records and 317,000 healthcare providers, and when it purchased another health data company called Phytel…and when it said it would snack on data from an untold number of Apple devices in a new partnership.

That’s the thing about overgrown artificially intelligent supercomputers. Those suckers like to eat. Which brings us into the picture—and by “us” I mean the not-so-artificially intelligent beings who provide all this feedstock. Collectively speaking, these are our medical records, after all. Our heart rates and sleep cycles and steps taken in a day. Even when the data points are anonymized—stripped from the identifiers that identify us individually—they are bits and bytes that point to our biology: our cholesterol levels, our genes and gene mutations, our outcomes in clinical trials.

Amazingly, though, there has been little resistance to handing it over. Many of us now volunteer to surrender our fitness-tracking data, generated by the ream on smartphone apps and Apple Watches (AAPL) and Fitbits (FIT). “We’re all suddenly willing guinea pigs,” says Matt Stempeck, the 31-year-old director of civic technology at Microsoft (MSFT), a position that didn’t exist a year ago. “We all want to be part of the experiment these days.”

Almost by definition, the class of early tech-adopters is more trusting of technology’s ability to help, and less fearful of its capacity to harm. And the widespread hope (and probably belief) is that these exabytes of human experience will lead to cures of disease, better medical technology, and earlier detection of illness. “It feels like a very small thing to do to contribute to research that might help a lot of people—especially with something like a wearable,” says Stempeck, who landed at Microsoft after a stint at the prestigious MIT Media Lab and freelancing on Google’s (GOOG) social impact team. “We’re basically trusting that the people sharing our data will do so in an ethical way that will protect our privacy,” he says—and besides: “Younger generations are sort of used to the idea that all our stuff is out there anyway, whether it’s Facebook (FB) or the NSA.”

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Sharing data, indeed, has become the new philanthropy—a social contract for the Millennial Age. And who knows? It just may be the most powerful thing to emerge from the sharing economy.