One thing that’s guaranteed to rile up consumers? Tacking on a monthly fee where there was once none. Mobvoi, which is known for making affordable Wear OS smartwatches, is the latest to join the subscription bandwagon. The company will start rolling out new sleep features to its TicWatch lineup this week, but if you want ‘em all, it’ll cost you $4.99 a month.

In a tweet, Mobvoi announced the new features would include sleep aid songs, AI sleep insights like sleep cycle reminders, historical sleep data, and more sleep-related metrics like maximum and minimum heart rate and SpO2. Of these new features, in-depth data like SpO2, min / max heart rate, and sleep trends will be available to subscribers only. Members will also get 50 sleep aid songs to choose from, as opposed to the 12 available for non-subscribers. A small caveat is that all of the upgraded sleep features are only available on its TicWatches that use the Mobvoi app. If you have a TicWatch but use a different app for your fitness and health tracking needs, this is all moot.

Mobvoi is currently offering its “VIP service” for a discounted $2.99 per month, provided users sign up by December 31st. TicWatch GTH 2 will also get a six-month free trial. But even at that price, you’re not getting a whole lot of bang for your buck.

This isn’t the first time we’ve seen a wearable company turn to subscriptions. Fitbit did it with Fitbit Premium, moving more in-depth sleep and health metrics behind a $10 monthly or $80 annual paywall. The Oura Ring also courted consumer ire last year when it introduced a $6 monthly subscription for insights that were previously free after purchasing the hardware. Meanwhile, Whoop 4.0 offers the hardware for “free” while charging a steeper $30 monthly subscription to gain access to its data insights.

Subscription fatigue is real, but there is at least some logic as to why this is an increasingly popular trend. One-time hardware sales aren’t enough to keep the lights on anymore. This is especially true for companies with ambitious plans for advanced health features. While wellness features don’t require regulatory approval, those with diagnostic capabilities like EKG and atrial fibrillation detection absolutely do. As the line between medical devices and consumer wearables blurs, the more likely it is that companies will have to actually grapple with regulatory agencies. The bottom line for wearable makers is that FDA clearance is a costly up-front investment — and that money’s gotta come from somewhere.

Mobvoi isn’t as well known for innovating health features as Fitbit, Apple, and Samsung are. But earlier this year, it announced the TicWatch GTH Pro, which Mobvoi claims can measure your long-term arterial health. That’s the type of feature that skirts the line between wellness and medical applications.

Yet from a consumer perspective, Mobvoi’s decision to experiment with subscriptions may feel like a slap in the face. For starters, the company hasn’t made a peep about its Wear OS 3 strategy in quite some time. Last year, Google said that 4100-powered smartwatches — including TicWatches — would be upgradeable to Wear OS 3 by the end of 2022. That deadline is fast approaching, and Mobvoi hasn’t uttered a word as to when users can expect the update to arrive.

Meanwhile, Fossil has already begun rolling out the upgrade as of October. Mobvoi also said it’d launch a new TicWatch powered by Qualcomm’s new Snapdragon W5 Plus chip this fall. It’s now December, and… crickets. Rolling out a subscription after months of radio silence isn’t exactly something you’d expect consumers to be pleased about. And, if Mobvoi’s Twitter mentions are any indication, they aren’t.