Attaching TV screens to treadmills isn’t a new concept. In fact, I recall seeing the little screens in fitness centers at least five years ago. Whether they were working or not is a different story entirely. But there’s no question that the feature has been possible for quite some time.

Why doesn’t every new treadmill have a screen built-in? Isn’t this infinitely better than making people look up at regular TVs and argue over the channel and volume? To me, this is a question of the benefit derived by users. For some people, the TVs are a wonderful convenience. But to other people — those who don’t use the screens — the TVs can be a huge annoyance.

Wait, how can a TV that’s turned off be annoying? Simple: the treadmill-mounted screens usually have a reflective surface, which acts like a mirror. Seeing your reflection when you’re running can get really annoying, really quickly. So for people who don’t have any interest in turning on the screens, the benefit turns into a major detriment.

With this in mind, the next time you’re thinking about a can’t miss feature, take a moment to consider if the benefits are truly universal. Otherwise, you may end up doing more harm than good.