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After a tumultuous four years as a public company, wearables pioneer Fitbit agreed on Friday to be acquired by Google for $2.1 billion.

The deal, at a 63% discount to Fitbit’s 2015 initial public offering price, marks the end of yet another independent hardware maker that couldn’t make it on its own. Now Fitbit follows the likes of vanished startups including Pebble, Flip, Palm, and Jawbone–and perhaps presages the fate of some still-public players like GoPro and security camera maker Arlo that have also seen their stock prices plunge.

For Google, the deal could give the company’s struggling wearables software unit a boost, although the track record of Google’s hardware acquisitions is replete with expensive failures. But Google can’t give up and cede the field to Apple, with its successful Apple Watch, at a time when smart wearables are becoming more useful and more popular than ever, not to mention the valuable health and fitness data collected from users.

Gartner this week forecast that the wearables market will grow 27% next year to $52 billion. And while Apple, Samsung, and some Chinese players such as Xiaomi came up multiple times in the report, Google and its wearables partners like Fossil and LG—both use Google’s software in their watches—were not even mentioned.

For recent investors in Fitbit, which has traded as low as $2.81 this year, the $7.35 per share acquisition price represents a quick profit. But for anyone who bought the stock before last year, particularly at the $20 per share 2015 IPO price, the buyout represents a significant loss.

The biggest winners in the deal, at least for a few years, are probably Fitbit’s 28 million active users. Fans of the company’s simple trackers, like the Inspire and Charge 3, and more capable smartwatches, like the Versa 2 and Ionic, love tracking their steps and competing in fitness challenges with friends via Fitbit’s app. Now their preferred wearables platform has a financially secure home inside one of the world’s most valuable tech companies.

The deal could also aid Google parent Alphabet’s already significant healthcare efforts, such as its Verily life sciences unit. Apple has signed up numerous prestigious health research groups to conduct studies with the Apple Watch, and Fitbit has made some similar strides. The “digitalization” of health and wellness data via wearables is a important growth area for the tech industry, UBS analyst Eric Sheridan noted. “Prior to this transaction, we saw Google as having relatively low exposure to this theme,” he wrote.

Just how much value Google will be able to squeeze out of the data that Fitbit collects from its users could be the make or break question for the deal. At least to start, Google promised to “never sell personal information to anyone,” adding that Fitbit health and wellness data will not be used to target Google’s ads. Google also said it would give Fitbit users the option to review, move, or delete their data. Google and Fitbit first started partnering on health data last year, when Fitbit agreed to use Google’s healthcare software formats and store data on Google’s cloud.

It’s unlikely that Google will garner as much trust from Fitbit users as Fitbit itself did, and that could lead to a wave of data deletions and defections. The deal is also unlikely to inhibit sales of the Apple Watch, says CCS Insight analyst Leo Gebbie. “It’s hard to see how it will erode the Apple Watch franchise in the near-term, as this is the clear device of choice for people who own an iPhone,” Gebbie says.

The data piece of the acquisition could also attract regulatory scrutiny. While Google is currently an also-ran at best in the wearables market, it’s obviously one of the dominant players in collecting and monetizing consumers’ digital data. That could draw the attention of antitrust regulators. And Google has already had to make multiple settlements with the Federal Trade Commission for privacy violations.

If regulators review Google’s history of hardware acquisitions, they may be less worried about Google’s market power. The $12.5 billion purchase of phonemaker Motorola in 2012 was an abject disaster, and most analysts believe the $3.2 billion acquisition of Nest Labs in 2014 has also yet to pay off, though Google still uses that brand name. Two years ago, Google made a more modest acquisition, spending $1.1 billion for HTC’s smartphone team. That bolstered Google’s Pixel phone efforts, though here, too, the company’s market share in phones remains miniscule.

“Google is uniformly bad at consumer products in our view, and appears to us to be intent on spending whatever it takes to prove our view wrong,” Wedbush analyst Michael Pachter wrote after the deal was announced.

Looking across the tech industry, acquisitions of struggling hardware players rarely succeed. Hewlett-Packard wasted $1.2 billion buying Palm in 2010, Microsoft’s $7.6 billion Nokia phone deal cratered, and Cisco Systems never did anything with Flip after paying $600 million, to name but a few examples.

But the stocks of some of the current crop of downtrodden hardware makers jumped on Friday, perhaps on hopes they will also be snapped up by a deep-pocketed suitor. Action camera maker GoPro jumped 6% to $4.40 in midday trading, still far below its $24 IPO price in 2014. And security camera maker Arlo rose 2% to $3.52, trailing its $16 2018 IPO price.

Why Google Is Buying Fitbit

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