DNA tests were a big holiday hit — in 2018. This past year, Ancestry and 23andMe DNA kit sales on their websites saw major declines, according to new data from Second Measure, a company that analyzes consumer credit and debit card data. As a result, both 23andMe and Ancestry have recently had layoffs.

In November, typically a big month for Christmas and other holiday gift buying, Ancestry’s US website sales were down 38 percent while 23andMe’s were down 54 percent compared to a year earlier, according to the data. The declines continued in December, down 15 percent for Ancestry and 48 percent for 23andMe, marking a year of declines.

From Second Measure’s data it looks as though consumer DNA test sales peaked around the holiday seasons in 2017 and 2018. That was just after Elizabeth Warren infamously released results from her own DNA test to prove her Native American roots.

It’s important to note that this data only includes online sales on the companies’ websites so wouldn’t have visibility into how many kits were sold through, say, Amazon or at physical retailers. Still, website sales should provide a good indication of general trends in consumer interest in ancestry and health genetics testing. 23andMe and Ancestry declined to comment on the numbers.

There are a few potential reasons for the declines, including market saturation, privacy concerns, and limited usefulness.

Market saturation

Ancestry’s president and CEO Margo Georgiadi, in a blog post about the layoffs, said that 30 million people globally have taken a DNA test — more than half of whom have done so using Ancestry. 23andMe has sold over 10 million DNA kits, most of which were in the US. Obviously, that leaves out a lot the world and even the US population, which has over 300 million people. Perhaps many of those who are interested in learning about their genetics and who can also afford to $100-plus for a nonessential item have already done so.

“The DNA market is at an inflection point now that most early adopters have entered the category,” Georgiadi wrote.

Or maybe having a sibling take the test might be enough for some people (it was for my family). While each sibling inherits slightly different genes from their parents, you can get a pretty good idea of your ancestry from their DNA test — assuming you have the same parents.

Privacy concerns

As more and more people took consumer DNA tests, a number of privacy concerns bubbled up, including how outside companies, law enforcement, and even foreign governments might try to use that data. In one high-profile case, police used DNA test info from third and fourth cousins, uploaded to a third-party site, to track down the Golden State Killer, highlighting that you’re not necessarily just revealing your own DNA when you take ones of these tests. These companies can sell your data to third parties, including Silicon Valley startups and pharmaceutical giants. Also, what happens with your DNA is governed by companies’ often dense privacy policies — policies that can be changed at any time.

In December, the Pentagon warned armed forces members not to take consumer DNA tests, saying, “Exposing sensitive genetic information to outside parties poses personal and operational risks to Service members.”

23andMe and Ancestry have upped their privacy bona fides by agreeing to voluntary guidelines that, among other things, require “express consent” from consumers before sharing their data with third parties. In 2018, 23andMe cut off third-party app makers from accessing your anonymized genetic info (customers had to authorize third party access). These companies offer a number of ways you can restrict what data you share and they also give you the option to delete your information entirely. But still, it’s likely that the damage has been done for the more privacy-conscious among us.

Limited utility

In addition to having numerous privacy issues, DNA tests aren’t necessarily as accurate as you might hope. Their perceived usefulness is limited, too. For many, a DNA kit might be a one-time affair.

To combat that, Both 23andMe and Ancestry provide a variety of different tests. 23andMe does offer a total of more than 150 personalized genetic reports that can detect everything from your predisposition to celiac disease to whether you drink too much caffeine. Ancestry offers options for “heritage tours” and “genealogy cruises” so people can plan vacations around their DNA results.

The companies continually display more findings for tests you’ve already taken as well as offer new tests you can buy, but from their web sales data it doesn’t seem to be proving enough reason to continue to shop with them yet.

Smaller competitors are trying different models in order to keep users interested and spending money. A new direct-to-consumer company called GoodCell is combining genetics and health test offerings with continual testing — maybe you don’t have diabetes now, for instance, but you might develop it in a few years — and biobanking. This means the company actually stores the blood they collect from you for the genetics tests, which a doctor or phlebotomist has to collect (so no spitting in a vial and mailing it in). The company has a $14.99 a month subscription model that includes these tests and storing your blood. They think your blood may be useful to you in the future as new cell therapies come online and that users will be interested in taking new types of tests periodically.

While the market for traditional direct-to-consumer genetics tests might be flagging, it’s likely that scientific advancements in our understanding of genetics and what we can do with the tests might lead to more interest down the line.