From the article (and thanks for posting that Ed):

Airline industry experts attribute the strong financial numbers to carriers filling almost every available seat and collecting fees for a long menu of on-board extras. In June, 87.4% of the seats on domestic flights were full, a new record for the industry.

The nation's largest airlines collected $3.3 billion in checked bag fees for 2013, compared with $1.1 billion in 2008.

Once the merger of American Airlines and US Airways is completed, four of the nation's carriers will control about 80% of all domestic air traffic, according to federal studies.

Time for some Restoration!