I use them for washing quilts and new fabrics. For laundry, they're too expensive for everyday use, but I do have a couple of clothing items...purples and reds...that still bleed and I've used them a couple of times when those items are in a mixed load.
If I give someone a quilt that has colors (like purples or reds) that might still bleed, I give a box of the Color Catchers and written washing instructions with the quilt.