In general there are 3 sizes of bath bombs offered. I will call the the golf ball size, the tennis ball size and the grapefruit size. We have always felt the smaller golf ball size is not adequate to provide the luxury bathing experience our customers are demanding. It really just seams to be down right cheap. The larger grapefruit size can retail for up to ten dollars per unit. This seems to be a little rich for a one time use item that most of our customers would have some price resistance. The medium size answered both of these questions and found a middle ground that keeps your customers coming back time after time.