Key Takeaways The main cabin won't be Delta's main source of revenue for much longer. Revenue from premium airfare will surpass main cabin sales within a quarter or two, Delta Air Lines (DAL) executives said Thursday. Revenue from premium airfare rose 9% year-over-year in the most recent quarter to $5.8 billion, while sales in the main cabin fell 4$6.1 billion, Delta said. Its results were the first from the major U.S. airlines. The figures and forecast reflect changing sources of demand in the airline ...