Just happen to catch this. I don't really promote Macy's, but noticed that 2 of the 3 promotional offers listed in their email from yesterday have typos that cause you to get the error...

Error 400: bad site code

In case you do promote them you may want to verify it. Look for "xN0" slapped into your affid. I am sure it was just a typo on their part.

Code:
htt p://click.linksynergy.com/fs-bin/click?id=AAAAAAAAAAAxN0&offerid=100713.10001373&type=3&subid=0