Definition: A box topper is an item inserted into a box of sports cards as an incentive for the purchase of the entire box. Box toppers are usually cards not available in packs of the product, but many items other than cards have been used in various products. A similar item inserted into a case of cards as an incentive is called a case topper.
Examples: Each box of 2001 Absolute Memorabilia Football included an autographed mini helmet as a box topper.