That reduces your yield.
Now, one way to think of it is that industry statistics for the last quarter would suggest that loss rates in Canada are running at about 4.5% on credit cards, but that's across the whole population of 100%. In terms of those 70% who pay off every month, you can't rightly attribute any losses to that population. It's the 30% who don't.
So if you have 4.5%, divided by 0.03%, all of a sudden the attributable loss rate to that 30% of the population is in the 14% range. Now you have 19%, less 14%, less the cost of funds, another four percentage points, and pretty soon you're down to a margin of 1% or 2% plus interchange.