You can't just walk into Target and buy this stuff!
I came right home and tested them out. The idea with pie weights is that you can pre-bake a crust without all those holes punched into the bottom of your crust. If you did nothing, then of course the crust would rise into a fun, albeit useless dome. The holes allow the steam to escape without raising the crust. To use the weights means leaving your crust intact which is important if your filling threatens to seep through the holes. Also, sometimes the holes split the crust and it comes out cracked and broken. Or sometimes the holes seal back up and your crust still rises.
I did a test and was surprised with the results. I baked two crust