What do you think are the advantages of having custom molded ear-buds? What are the problems people have with ear-buds that this will solve? Is this a good idea or just a gimmick? Why?

One advantage of having custom molded ear buds is that they will always fit.  Sometimes when ear buds are too small they constantly fall out, or sometimes when ear buds are too big they hurt when you put them in.  With custom molded ear buds they fit perfectly, not too big not too small.