Rock-Tenn produces packaging products. They make cartons that will hold a dozen Dunkin' Donuts, waffle fries for Chik-fil-A, Gillette razors, Haagen -Daz ice cream, express mail envelopes for FedEx and much more. Rock-Tenn business fluctuates depending on consumer demand. As plastic products become more expensive companies turn to cardboard and paper to package their products. A sales representative from a paper producing company calls on Rock-Tenn routinely every month to review their ordering needs. The monthly sale of paper to Rock-Tenn would constitute a: modified new buy new buy