There are so many advantages to having a reusable coffee cup! Firstly, it's cheaper! You can go into pretty much any coffee shop these days with your own coffee cup and they will offer you a discounted drink. It makes sense as you don't need to pay for the single use cup anymore. Like quite a few plastic-free swaps, you might have an initial cost but in the long run it works out miles cheaper.
Other advantages include keeping your drink warmer for longer. They can also prevent leaks and spills and they don't cost the world.
The main thing, however, is that you're obviously doing good for the planet. There are some crazy statistics out there that talk about how many disposable coffee cups go into landfill each day. Let's not focus on the negative, but instead just decide to go for it, pick your favourite colour and add it to you basket!