More Pages, Higher Sales

With food or gift catalogs, I've seen new products tested where the new products were too different from existing best-sellers, and consequently the new products wouldn't sell at all. Net sales increase: zero.

And on the other hand, I've also seen tests where, if the new merchandise was too similar to existing best sellers, they sold well, but only by cannibalizing the sales of older best-sellers. Net sales increase: again, zero.