I was at a gas station the other day, filling up my tank with gas. The owner of the little establishment was hovering nearby, and someone handed him some bills, remarking, "You probably prefer getting paid in cash, eh" Being a nosy sort, I turned around to hear his response. He surprised me by saying that he greatly prefers that customers use credit cards. Huh My understanding is that merchants who accept credit cards have to fork over to their hosting bank a fee and/or percentage of the sale for each transaction. Why wouldn’’t good old cash be preferable The answer took me aback, but upon a little reflection, it made a lot of sense: robberies. Gas stations, convenience stores, and other businesses are frequent targets of bandits. Many who work in these places have been shot and sometimes killed on the job. It’’s a serious problem. A 2002 article from the Christian Science Monitor cited "... an uptick in store-clerk murders in the past three years, jumping from 78 to 111 between 1999 and 2000 alone. A quarter century since convenience stores first started staying open round the clock, late-night clerking has become one of the most erous jobs in the country — especially relative to the wages of roughly $7.33 per hour." A more recent Palm Beach Times article stated that, "Based on past numbers from the Bureau of Labor Statistics, it’’s estimated that over 700 convenience store workers, particularly cashiers, will be murdered during robberies this year in the United States. A convenience-store cashier job is the 10th-most erous occupation in the United States according to the U.S. Labor Department, which classifies being a convenience-store cashier job as more erous than being a firefighter. What can we do about this sorry state of affairs Well, legislation has been proposed to require more safety training for these workers at risk. But taking a perhaps unusual approach, we may be able to help these workers if, the next time we find ourselves at our local 7-Eleven or Chevron station, we whip out our American Express or nifty Fool credit card and pay with that. If over time the stores become perceived as places that are not full of cash, they’’ll likely attract fewer bandits. There’’s reason for at-risk workers to be hopeful. According to Credit Cards Magazine "The National Association of Convenience Stores says that since Hurricane Katrina, gasoline purchases paid for by credit cards have risen from 70% to 80%." What is the author’’s purpose of writing this passage