fitbitLots of people are excited about the upcoming IPO for Fitbit, the ubiquitous health tracking device maker, and there are plenty of reasons for this excitement. Sales for the devices are showing strong growth and, if you’re like me, half the people you know are using Fitbit to track their personal health and activity goals. But I can’t get over the similarities between Fitbit (and most health tracking devices) and other popular gadgets that turned out to be just features and not actual products.

Think about the iPod. Once upon a time it was the most popular gadget out there. Nearly everyone had multiple iPods (or some other MP3 player) that was their go to device for listening to music. Or maybe you remember the Flip camcorders. People loved these inexpensive gadgets that made shooting high quality video as easy as taking a picture.

But as smartphones increased in power and capabilities, many realized that they get a pretty good music listening experience out of a device they were already carrying. Same went for video. Many smartphones today can take really good quality video. There are even examples of movies that have been shot entirely using iPhones.

What happened to these seemingly unstoppable devices is that they turned out to just be a feature of something else. Sure, the dedicated devices had some benefits over the smartphones, but for most people, the convenience and decent quality outweighed those benefits. And the potential for the same thing to happen to health tracking devices like the Fitbit seems to be pretty high.

The main threat to the growth of Fitbit is clearly smartwatches like the Apple Watch. These wearable devices have most if not all of the capabilities of dedicated health tracking devices and provide a lot of extra functionality as well. If you’ve already dropped a good amount of cash on a smartwatch, why would you bother to wear a Fitbit as well? Would it be that big a surprise to see health tracking wearables go the same way as MP3 players, point and shoot digital cameras and low cost camcorders?

Of course, the Fitbit has some breathing room to make a move that could ensure its continued growth. While there’s lots of excitement around the Apple Watch right now, smartwatches are hardly ubiquitous and are probably a couple of years away from being a standard gadget that many people have.

Also, dedicated devices like the Fitbit right now have a much longer battery life than most (though not all) smartwatches, which should help fitness obsessed people stick with these devices.

So the key right now will be what Fitbit does to maintain their relevance.

One move would be to become a full-fledged smartwatch. Some of the higher-end Fitbits already have some of these capabilities and, with not too much work, they could add on many of the same features as most leading smartwatches. Sure, they would be competing directly with Apple, Google, Samsung and other major vendors, but that’s going to happen anyway. With their large installed base, they would have a good chance of maintaining relevance.

The other tactic would be to become just a much better fitness tracker than multi-purpose smartwatches. While this may not lead to massive growth, they could, like high-end cameras, still maintain popularity within a specific niche.

Either way, the Fitbit and other health trackers are facing some serious competition. Smartwatches already have some very good fitness tracking capabilities and, by leveraging their other capabilities, can offer integration and additional features that could be tough to match.

So right now I’d temper that enthusiasm. My gut tells me that health tracking is a feature that will be found in most wearables. But right now it’s a marathon, not a sprint, and companies like Fitbit have a chance to make the right move that will keep them in the running.