I just got my Mastercard statement from Citibank, and found this:
Apparently the ANNUAL PERCENTAGE RATE on purchases is 36%, corresponding to
a "Nominal APR" of 17.74%, while the two are the same on advances.
(Click on the image for the full scan.) The percentage rate I’m more interested
in is the proportion of Citibank customers to whom this kind of thing makes
any sense at all. I know I’m not among them.