As long as the Macy's gift card rules allow this you should be fine. That said, it does look like it violates the T&C:
http://www1.macys.com/service/gift/terms.jsp
Delta Points had a post today re ethics. I posted a comment about the ethics of representing one's affiliate credit card as "the same" as a better offer, when it is not true (see
here for an example of someone doing that with the US card).
No surprise, I was censored yet again. I guess actions speak louder than words for some bloggers.