Traffic on the nation's airlines has been picking up, but carriers are still offering fare sales and other inducements to keep the fragile recovery in travel moving ahead.
The latest example is Southwest Airlines.
It says it will give members of its frequent-flier program free travel by taking four roundtrip flights.
That's twice as fast as fliers would normally earn a trip.
Southwest said customers who buy a higher-priced "Business Select" ticket will earn a trip even faster.
The offer covers travel through May 26, meaning it expires before the beginning of the peak summer travel season.
