Maybe you just haven't looked into it? Before Canada cracked down on them the rate could be over 3000% when calculated annually. It may still be in some provinces.
In the U.S. you have states like Missouri where APRs of 2000% percent aren't uncommon.
The one regulation in the State of Missouri that differs from other states is that there are limits on the interest rates that you pay. The total APR that you can charge in the State of Missouri is 75%, including all interest, fees, and other costs associated with the loan. This differs from many other states where there are no rules that limit the amount of interest that can be charged.Source: Missouri payday loan interest rate