One of the advantages of having a car that constantly receives software updates is that--in theory--it improves over time. At least, that's what you would expect. You would expect that whoever made the software on that car is thinking about how to make the overall experience of using and driving that car even better. 

If you've driven any car in the past decade, you know that's not necessarily the case. Sometimes software updates make your car worse. Take Tesla, for example. Last year, the company released a software update that made it harder to do things like turn on the defroster--something that seems important if you live in the vast part of the company that gets really cold half the year.

Sometimes, however, those software updates come with seemingly small changes that end up making a very big difference--in a good way. Last month, Tesla released a software update that, among other things, added the ability to link multiple Spotify accounts to different driver profiles. That probably doesn't seem like a big deal, but it actually is. Here's why.

First, if your car allows you to create different driver profiles to fine-tune different settings based on who is driving, and, if that car allows you to log into streaming services like Spotify, Tidal, Netflix, etc., it makes sense that you should be able to link different accounts to those driver profiles.

And, if Spotify will let you have a family account so everyone in your family can have their own playlists and favorites and listening styles, and if Tesla is going to let you sign in to your Spotify account, it only makes sense that you should be able to link your individual account. That's just the way the connected world works in so many other instances, so why shouldn't it work here?

It's the kind of thing that just makes sense. The fact that you couldn't do it before was sort of irritating. It meant that no matter who was driving, if they listen to Spotify, it's all feeding back into one account--which defeats the whole point of having a family account to begin with.

The reason this matters is that your number-one job is to make the experience better for your customers. If you're updating software, make it solve more of their problems more easily.  

I get it--a software update to something as mundane as whether your Spotify account is linked to your driver profile doesn't really seem like something worth getting excited about. But hear me out. 

I own a Model S, so I feel like I'm as qualified as anyone to point out that Tesla spends a lot of time on things that don't make the experience of driving a car better in any real way. They might be fun, or cool, but that's not the same as useful. 

For a long time, it seemed as though Tesla had forgotten that people who buy its cars might actually enjoy driving them. I know Elon Musk is all-in on the idea that someday cars that drive themselves will be safer than those driven by us humans. That's probably true, but for now, it's still up to us to do the driving, despite what Tesla says about its Full-Self Driving capabilities

That's why it's frustrating when the company does things like making almost everything a touch control, eliminating traditional dash displays, or taking away the steering wheel in favor of a far less useful navigational control input device. None of those things are especially useful. They might seem cool, but they don't make the experience better.

That's the lesson, by the way. Sometimes it's easy to get distracted thinking about what's cool while losing sight of what's useful. If you're building a car, above all else, everything about it has to be useful. People's lives literally depend on easily understanding how to control the vehicle. Sure, selecting your music isn't exactly essential, but it sure is useful. It makes the experience better.

Sure, there's value in making things that are cool, especially if that's your entire brand. The thing is, if you're adding something cool that makes the experience worse, you're doing it wrong. That's true whether you're building cars, smartphones, coffee mugs, or socks.