It's become popular to demonize the credit card industry, but that's not entirely fair. Yes, some rates and fees can seem excessive, and yes, aggressive marketing tactics can make it all too easy for people to get hooked on debt. Still, credit cards play a vital role in the modern economy. They help provide liquidity--the convenient and timely access to capital that facilitates day-to-day transactions. Capitalism could exist without credit cards, but only at a much slower pace.