It’s actually incredibly smart design.

I’ve seen a few tweets recently where people accuse Snapchat of having a terrible user interface. For example, this got retweeted in to my feed earlier:

While Snapchat’s UI may not be the most intuitive (to adults at least), it does serve a few important functions:

1. It keeps the adults out

Teenagers love Snapchat. They’re addicted to it. It’s currently the hot service. Facebook, Twitter and Instagram used to hold that 👑. Now it’s Snapchat.

Snapchat provides a place where teenagers feel safe. The content you post is ephemeral — it disappears very quickly. There’s no risk of it hanging around on the internet and biting you in the future. Because the interface confuses most people over the age of 25, it’s unlikely that your parents will be able to find out what you’re up to (for now). You don’t have to think carefully about what you post. You have more fun. It’s like hanging out with your friends in real life.

2. It makes people talk about Snapchat

Every time a new feature is added to Snapchat, thousands of people ask each other how it works. Each time, that chatter raises awareness of Snapchat.

The best example of this is when Snapchat launched lenses last year. As soon as I sent my first selfie with a lens applied, many of my friends replied asking how I did it. People talked about it on Twitter and Facebook. And since lenses launched, Snapchat has exploded. It’s a super fun feature.

3. When you learn the UI, you invest in the product

For adults, it can take a bit of time to learn Snapchat’s UI. But Snapchat is fun. Each time you learn how to use a new feature, you get a little dopamine hit. Same when someone adds you as a friend, same when someone sends you a funny snap. The more you use it, the more fun it becomes. You’ll tell your friends and they’ll join. You’ll force your colleagues to download it, and you’ll get them addicted. And then the network effects lock you in.

Snapchat has also been adding more features recently. The app has been climbing the ladder, and is on the way to becoming a full blown media platform and messaging app. It’s here to stay, and it’s going to keep getting bigger.

If you don’t have Snapchat yet and don’t know where to start, I recommend checking out Mark Suster’s 101 for Old Folks, and Buzzfeed’s Adults Guide to Snapchat.