Once upon a time a young mother bought some side-snapping fitted diapers for her baby. He wore them for many months before outgrowing them. Then his younger sister wore them for many more months, as did the next sister after that. By this time the diapers were quite worn. The mother was done having children, so she didn't need diapers anymore, but her friend had babies so she offered the diapers to her friend.
I love them! And they'll last through another kid or two.