Like many credit cards, it comes with rewards "points". I get one point for every $1 I spend. The information that came with the card includes a table that begins as follows, which purports to show "how fast your points... can add up":
What, are people so stupid that they can't multiply by one?
(Of course, there are much more serious quantitative-illiteracy issues involved with credit cards, namely that people don't realize how much they get gouged on the interest rates, or just how long it'll take them to pay off the thing -- and how much interest they'll pay -- if they make the "minimum payment". But I won't go there.)