The race to own your genes and health data is heating up.

This week, Ancestry.com–long-known for helping genealogy geeks map their family trees–announced a new product dubbed, of all things, AncestryHealth. The goal is to create for consumers a digital record of every disease that’s plagued their family over the years, as well as each of their family members’ cause of death.

When you log on to AncestryHealth, consumers who already have a built family tree will have the option to manually input their family’s roster of medical maladies: cancer, hypertension, aneurysms, diabetes, Parkinson’s, etc. It’s not all that different from the About section Facebook is always hounding you to fill out. But the potential uses are much more profound: the promise is better healthcare, as opposed to less annoying ads.

“Family health history is one of the most valuable and underutilized tools,” Ken Chahine, the executive vice president for AncestryHealth, told me. “Our vision for AncestryHealth is to try to create a product that brings the utility of family health history to the consumer, and ultimately to your physician.”

Right now, you have to print to share (how arcane!), but Ancestry says it’s working on a mobile app and partnerships with electronic health record companies to make sharing your family health history with friends, family and doctors seamless. AncestryHealth data isn’t yet complemented by genetic information, but that’s coming. The company announced they had scanned the genomes of 1 million people, a milestone they reached just a little over three years after launching their DNA service, AncestryDNA. That puts it head to head with 23andMe, which launched its genetic test in 2008 and reached 1 million customers last month.

“If you think about the health space,” he said, “everything is sort of segmented and siloed. We want to break that mold. We’d like to get everything from pedigrees, to your relationships, to your genetics, your family health history and other records and start bringing that together.”

Call it what you want, but the message is clear: Ancestry is morphing itself into a social network built on geneological, medical and genetic information. Think Facebook, but for health, minus the ads.

And in doing that, it’s joining some steep competition in the quest to win over your DNA. Google-backed genetics analysis company 23andMe is its most direct rival. It recently announced it was hiring a Genentech exec to help it develop drugs, using its DNA database, in house. But there are others. Google recently launched Google Genetics, a service that lets hospitals store genomes for an annual fee of just $25 a pop. In May, the MIT Technology Review reported that Apple was partnering with researchers to collect genetic information through ResearchKit, the company’s open-source platform for medical research. Kaiser Permanente paired the genetic information of 100,000 of their clients to medical records going back 20 years in some cases. Earlier this year, President Barack Obama proposed building a database containing the genetic and health history information of 1 million people.

Companies, universities, healthcare organizations and the government are in an arms race to amass databases of genetic information that weave together genetic, sensor, lifestyle, environmental, microbiome and medical-record data. The hope is that they’ll be able to use that to glean insights about people’s risks for certain diseases and what drugs might work best for them.

There’s a lot of money to be made in that. In 2012, non-profit R&D firm Batelle released a report estimating that the genetic testing industry generated $16.5 billion and 116,000 jobs. That same year, insurer UnitedHealth’s Center for Health Reform and Modernization estimated that spending on genetic testing could total somewhere between $15 and $25 billion by 2021. In January, 23andMe announced a series of multimillion-dollar deals with big pharma, giving them access to their data so they could use it to develop better targeted drugs. In April, IBM acquired Explorys, a company spun out of the Cleveland Clinic that owned the anonymized health records of some 50 million people, for an undisclosed sum.

“There is a marketplace for data on patients, 23andMe and Ancestry are the newest of the players to the table,” said Atul Butte, the director of the University of California, San Francisco’s Institute for Computational Health Sciences.

In that light, it makes sense that Ancestry would want to leverage its already large database on families to get into the genetics and health game.

Traditionally, the company has made its money by signing up new subscribers or upselling or cross-selling existing ones on new products. You sign up for its family tree-making service, next thing you know you get a message saying you should try AncestryDNA, which only costs $99. By then, they’re “hooked in,” Chahine says, because their family histories, and possibly their genes, are on the site, plus they might be interacting with far-flung family members through the service, too. It’s the good, old network effect. Once you have a critical mass, it’s hard to leave.

Moving forward, though, that’s only going to be one branch of the company’s money tree. “Data licensing is another piece. That data could end up being valuable for research,” Chahine said. “We want to help enable better diagnostics, better drugs, all of that.”

To whom would they be licensing the data? Well, most likely it would be to big pharmaceutical companies like Genentech, Pfizer, and Novartis, following in the footsteps of 23andMe. Chahine says Ancestry is actively trying to broker similar deals, though he wouldn’t give any details.

To put all that data to good, financially savvy use when the time comes, Ancestry has hired Cathy Petti, a former exec at Novartis, as its chief health officer. She’ll be in charge of the company’s dealings with government regulators as they move to market a direct-to-consumer genetic test. Although they’ve got expansive genetic data on 1 million people, the only information they can disclose now is a breakdown of ethnic heritage, along with possible relatives because Ancestry doesn’t yet have approval from the U.S. Food and Drug Administration to conduct medical diagnostic tests. Petti has begun working with the FDA so that they can make known whether someone is at higher risk for conditions like cystic fibrosis or breast cancer.

And that, paired with the family history data Ancestry has, is the kind of stuff that’s really valuable to big pharma. Armed with genetics and information about people’s past and present health statuses, drug developers hope they’ll be able to home in on medications that have the greatest chance of making it through the long, arduous and expensive clinical trial process and that these will work on the patients that need them.

But to sell pharmaceutical companies on that promise, Ancestry and others need people to keep inputting data. The economic success of companies like 23andMe and Ancestry rests on consumers’ willingness to share their personal information. GoogleHealth and Microsoft’s HealthVault, two previous attempts at building personal health records, flopped because they were too clunky and people stopped using them.

Services like 23andMe and Ancestry, offer consumers great value, and that’s why millions of people are using them, says Butte.

Since its inception, 23andMe has had a user-friendly interface through which they’ve deployed thousands of surveys, amassing information about everything from whether people have been diagnosed with chronic fatigue syndrome to whether they’ve experienced a seizure or depression. In 2012, the company allowed consumers to share their data with third-party apps, the way you might link your Facebook profile to your Netflix account. On Ancestry, your family health history– that your grandma died of cancer, that your mom has high blood pressure, or that three cousins are diabetic — has to be manually added to your profile, but again, it’s easy. And, Chahine says, the company is considering linking to health data platforms like Apple’s HealthKit, which would allow them to import data from activity trackers, heart monitors, food logs, and other health-related apps. Plus, these websites have always been sold as tools that empower consumers with data and have the potential to rid the world of diseases by agreeing to “donate” their data to research.

But these companies aren’t in the business of humanitarian work. They answer to shareholders and investors. And their terms of service agreements reflect that. 23andMe makes clear that “by providing any sample…you acquire no rights in any research or commercial products that may be developed by 23and­Me or its collaborating partners.” As for Ancestry, the language in the TOS recently changed to remove phrases like “your information” in favor of “personal information.” The change is subtle, but telling. Chahine said it was part of bigger strategy that “required being able to have the right consents, and making sure the consumers understood their rights and how the data was going to be used.”

But you get the picture. So it’s important to keep in mind how we share our most personal information, lest it be sold to the highest bidder. Earlier this year there were rumors that Ancestry was up for sale, and your data with it.