We're thinking about launching a starter credit card for US college students. Can you estimate, on the spot, how much US college students spend on credit cards each year, and how big the interchange revenue pool is for issuers?

我们想推一张专门给美国大学生的入门信用卡。你现场估一下，全美大学生一年在信用卡上刷多少钱？这能给发卡行带来多大的交换费收入池？