When is it useful to borrow bitcoin? Well, when you have cashbacks on primedice or some other very good deal where you can get a very good deal in something like gambling, and you have a 50 percent chance to double your money and then make a net profit of like 90% (200%-110%, which is basically the normal loan repayment rate), and a 50 percent chance to lose only 10 percent of whatever you borrowed. This is a good deal, and has a high profit and low loss rate.