For a start, they are more affordable than normal beds and mattresses. They are also very useful if you have a small house or even a single-room apartment. They can double as a sofa or a chair, and can easily be folded or rolled up and stored away in a cupboard. If you have a guest staying overnight, a futon is easy to roll out. If you have a futon as a sofa, then it’s easy to fold out into a bed at night, and back to a sofa in the morning.