As of October 2015, American consumers owe $8.17 trillion in mortgages, $900 billion in credit cards, and $1.19 trillion in student loans. Home mortgages, credit cards, and student loans occupy the most of the consumer credit market.
The consumer credit market is the dream paradise of money merchants, known as moneylenders. Just as pharma companies sell drugs to make money by way of profit, money merchants sell money to make money by way of interest. Note again, money merchants sell money to make money.