I use the large colored rubber bands for game boxes so no worry of game pieces everywhere. I like having a variety of colors in my rubber bands: so partially looks.
I use the big rubber bands on my radio control airplanes to secure the wing to the fuselage. They do a wonderful job on the "old timer" R/C electric airplanes that I fly as they are so much longer than the usual rubber bands and put less stress on the wing hold-down dowels.