Because I love fabric! I buy them because they give me a variety of designs to use in anything I want to make. I can cut just about any piece I want from one 10" square, charm packs are pure delight and same reason as layer cakes; they let me see all the fabrics in a particular line and then if I want or need yardage I know exactly what I want. Layer cakes and charm packs are my favorites. I've made so many wonderful things using these pre-cuts while I have yardage, that I just had to have, that is still laying on my shelves. Oh and to top that, I'm a fabriholic.