Product review (5 stars): Three racks is better than two
Yup.  This is helpful.

At first, I thought I would like to be able to bake more things at once, so I had purchased a contraption for stacking baking sheets in the oven.  It was from Betty Crocker, but still a piece of trash.

Then I thought- why not just get a third oven rack? And it was the best idea I have had for the kitchen in a very long time.