When I first saw them, I thought they may be a cheap way of getting many different fabrics without having to buy the minimum width. I have not done the proper math on them yet, as the jelly rolls here are $80, with some cheaper brands being around $35 -$50. That means I would have to have a specific project in mind that required lots of strips before I would get one.
I did see a video from the Missouri Quilt Co that showed a simple way of making an Amish star using the jelly roll, and that has interested me.