Talk to any retailer, or better yet, a wholesaler and you`ll hear about dollars per square foot (sometimes inch). It means if Wal-Mart is going to give you a 4x8 foot piece of an aisle, that`s 32 square feet of their floor space. They have a formula as to how much money each square foot should be generating per period.
So if you can put 10 boxes on a peg and each box-on-a-peg takes up say 1 sq foot, that`s a number (1 foot, 10 boxes deep). If the cardboard, flatter package allows for 12 per peg, that`s an additional 2 units sold per foot.
Even with the box (looked at the gallery), think of the VHS tapes, about the same size box. They use either a glue-on peg hanger, or the end of the box folds in, with a hole for a peg. Easy enough to do and still keep the box. :-)