Children grow too fast, 7 sizes in their first 2 years. This results in parents having to buy a lot of clothes that are only used for a few months.
Petit Pli (http://petitpli.com/) makes versatile children clothing that adapt to children's size. The continuous size adjustment is a new way of approaching product design.
It's an example of how products can be designed for longevity, adapting to our needs.