We ran a bonus cashback test: 100,000 customers got an extra 1% back on all spend for one month, and another 100,000 were a control group. During the month, the test group spent $1,050 per customer versus $1,000 for control, and our interchange is about 2% of spend. Marketing says the campaign lifted spend by 5% and was a success. What's your take?

我们给10万个客户做了一个加赠返现活动：一个月内所有消费额外返1%，另外10万人是对照组。活动月测试组人均消费1050美元，对照组1000美元，交换费收入大约是消费额的2%。营销说活动拉动了5%的消费，很成功。你怎么看？