Final answer:
Green marketing or sustainable marketing is the strategy employed by Hallmark Greetings when they produce cards on recycled paper.
Step-by-step explanation:
The example given, where Hallmark Greetings produces cards on recycled paper, is an example of a marketing strategy that addresses ecological interests. This strategy is known as green marketing or sustainable marketing. It involves promoting products or services that have eco-friendly features or are made with sustainable materials.