To learn more about the CNBC CFO Council, visit cnbccouncils.com/cfo With Spirit Airlines gone from the skies, travelers now have fewer lower-cost options waiting in the wings during the busy summer season. Americans may need to get used to it, as the changes taking place in how we fly could become permanent. For many years, airline efforts to create loyalty programs that keep customers sticking around could not compete with the one deciding factor for customers when purchasing a ticket: price.