The smart ring era is here and tech companies are fighting for your finger. Will you wear one?

• The smart ring era is here. Samsung has entered the space with its Galaxy ring.
• Apple is said to have considered a ring too.
• There's a good reason tech companies want to own your finger: subscription revenue.
• This article is part of "5G and Connectivity Playbook," a series exploring some of our time's most important tech innovations.

Prince Harry wears one. Mark Zuckerberg and Jack Dorsey track their sleep with theirs. Jennifer Anniston says Jimmy Kimmel got her hooked on hers.

Smart rings are having a moment. In fact, they've been having a moment for a few years. But one of the headline acts of Mobile World Congress this year is Samsung's Galaxy Ring — a smart ring that tracks heart rate, sleep, and even fertility. Analysts think it has the potential to dominate the market.

Samsung is only teasing its for now — the ones at MWC are just prototypes, and the device won't be on sale until later this year — but the company's arrival has made a splash in Barcelona. Honor, the mobile business spun out of Huawei, also announced this week that it's working on a smart ring.

The tech companies see this as a fruitful new play. Until now, Oura has been the biggest name in town, but there are plenty of other startups vying for that finger real estate, with rings that track your health and even let you make payments wirelessly with NFC.

When IDC noted growth in wearables shipments in Q3 of 2023, it attributed it in part to emerging categories such as smart rings. The arrival of more smart rings would " jumpstart the new form factor in the coming quarters," the analysts wrote.

Avi Greengart, president and lead analyst at Techsponential, told Business Insider at MWC that Samsung's Galaxy Ring "validates the smart ring category."

And then there's Apple, whose specter looms over any burgeoning new gadget category.

Last week, Bloomberg's Mark Gurman reported that Apple had explored a smart ring of its own, although such a product wasn't currently in development. Rumors of an Apple smart ring have been simmering for over a decade — mostly due to a string of patents the company has filed for. But Gurman reports that some folks inside Cupertino are campaigning for the company to build such a wearable device, which would be focused on health and fitness.

Apple's wearables division now accounts for 10% of the company's revenue, so there's good reason for interest in this space. But Apple tends to take a wait-and-see approach to launching new products, so there will no doubt be some executives in Cupertino closely tracking the success of Samsung's smart ring (and with the Apple Car now dead, maybe some engineers have a bit more free time on their hands).

Apple has managed to dominate the smartwatch market, but there's a huge sector of people who don't wear watches or don't want to replace the wrist watch they have. Some people want to track their health but don't want a device buzzing on their wrist all day.

There's another benefit: longer battery life. Because there's no screen (at least not on the rings we've seen so far) these devices are less power-hungry and can go days without a charge.

The field of sleep science is ever-evolving, but companies such as Oura claim the finger is a superior place to track sleep.

"People are starting to realize the importance of improving their sleep quality, and measuring sleep metrics on a finger is more accurate than a wrist," Greengart told Business Insider.

There are still obstacles to overcome. Right now a lot of the rings are chunky, but they should slim down over time as the technology evolves.

For companies like Samsung and Apple that already sell smartwatches and other fitness trackers, there's a risk of cannibalizing their other wearables where people don't want to wear a smartwatch and a ring — but it might be worth it.

There's another good reason tech companies are eyeing smart rings right now, according to IDC analyst Francisco Jeronimo: subscriptions.

Smart rings could prove lucrative for tech companies in the long run if users pay a monthly fee to access health insights, AI coaching, and — maybe one day, far in the future — deeper health metrics like glucose monitoring and blood pressure.

Whoop, a wearable fitness band that relies on a subscription model, has carved out a niche in giving users super-deep data on workouts and recovery time. Ultrahuman, another wearable tech company, makes a smart ring called the Air that also zones in on recovery time, letting you know how long to wait after a workout before hitting the weights again.

Samsung has hinted it's thinking about a health subscription service, one that could leverage built in artificial intelligence tools (think a digital doctor that has all of your health information to hand).

"For the companies, it's all about selling subscriptions and services. That's why they're jumping into the category," said Jeronimo.

"If the price point is right, Samsung will do extremely well."