Retailing giants racked up huge profits in 2020, driven by a surge in online sales, while many small businesses struggled amid COVID-19 closures and shoppers leery about venturing into brick-and-mortar establishments. Amazon’s third-quarter earnings report for this year, the most recent available, notes an operating cash flow of $55.3 billion for the 12 months prior to Sept. 30, up from $35.3 billion for the same period in 2019. Net sales were $260.5 billion for the three quarters ending Sept. 30, 2020, compared to $193.1 billion for the same period last year. Net income, a measure of profit, for the three quarters ending Sept. 30, 2020, was $14.1 billion, compared to $8.3 billion for the same period in 2019, a 70 percent increase. According to Amazon’s forward guidance for the fourth quarter, the company expects net sales of between $112.0 billion and $121.0 billion, or growth between 28 percent and 38 percent compared …