Discover operates a high-margin, dual-revenue direct banking and payment network business model characterized by strong net interest margins (NIM) and proprietary transaction network fees. Its commercial revenue engine spans four primary pillars: First, Credit Card Net Interest Income (~72% of revenue), earning interest spreads on over $105 billion in revolving credit card loan balances under the flagship Discover it card program. Second, Merchant Discount & Network Interchange Fees (~14% of revenue), collecting interchange and merchant processing fees across the proprietary Discover Global Network, PULSE debit switch, and Diners Club International. Third, Consumer Loans (~8% of revenue), originating fixed-rate personal loans and student loans with disciplined underwriting. Fourth, Direct Banking Deposits (~6% of revenue), gathering over $80 billion in low-cost consumer deposits via high-yield digital savings accounts, CDs, and cashback checking accounts without expensive brick-and-mortar branches.