Addition Problem

"... and as an added bonus ..." We see this come-on everywhere nowadays, but it makes no sense. After all, a bonus, the dictionary reminds us, is "something in addition [italics mine] to what is expected or strictly due" (Merriam-Webster's Collegiate Dictionary, 11th ed.). So, an added bonus is something added to something added. "Bonus" is a solid noun, perfectly capable of standing alone. It shouldn't be rendered meaningless by marketing drivel.