( CNN ) -- What makes airline passengers happy ? Sometimes it 's as simple as a smile . Along with mobile check-in , Wi-Fi in the air and other technological advances , the simple act of airline employees smiling is increasing airline passenger satisfaction . Airline passenger satisfaction has improved to its highest levels since 2006 , according to J.D Power & Associates ' 2013 North America Airline Satisfaction Study released Wednesday . U.S. airlines collect $ 6 billion in fees . `` Traditional carriers have improved significantly across the entire passenger experience , and it is a positive sign to see them turn a corner and starting to rise again , even as there is still more opportunity to improve , '' said Jessica McGregor , senior manager of J.D . Power 's global travel and hospitality practice . `` While satisfaction with low-cost carriers only slightly improves , greater gains in the rest of the experience are masked by lower passenger satisfaction with cost and fees . '' The study measures passenger satisfaction with North American airlines based on the following criteria in order of importance : costs and fees ; in-flight services ; boarding , deplaning and baggage ; flight crew ; aircraft ; check-in ; and reservations . Satisfaction improved in every category , but the largest yearly increases were in the boarding/deplaning/baggage , check-in and aircraft categories . JetBlue , Southwest top the airline rankings . For the ninth consecutive year , JetBlue Airways ranked first for satisfaction among all North American airlines . JetBlue also earned the top score among low-cost carriers for the eighth year in a row . Southwest Airlines was a close second among discount carriers with 770 points to JetBlue 's 787 . Airlines are ranked on a 1,000-point scale . `` Above all , we 're grateful for our 15,000 crewmembers that inspire humanity each and every day by going above and beyond to deliver the best customer service in the skies and on the ground , '' said JetBlue spokeswoman Allison Steinberg , via email . Alaska Airlines topped the traditional carrier rankings , with Delta Air Lines in second place . Alaska scored 717 points and Delta scored 682 points . `` We 're honored to receive this prestigious recognition from our customers , '' said Alaska Air Group President and CEO Brad Tilden , in a statement . `` Receiving this award six years in a row is a credit to the 13,000 Alaska Airlines and Horizon Air employees who show their dedication to our customers every day and on every flight . '' Overall satisfaction with the airlines improved to 695 on the 1,000 point scale , a 14-point increase over the 2012 survey . The power of a smile . Despite passengers choosing to check in online rather than talk to someone at an airport ticket counter , how an airline 's employees treat customers still counts . Passengers who are greeted by airline staff with a smile , even infrequently , report satisfaction scores that are 105 points higher than among those who never get a smile . Passengers who report airline staff smiling at them consistently report satisfaction scores that are 211 points higher than those who do not get any airline smiles . `` Airlines do n't have to invest millions of dollars in the aircraft to get employees to smile , '' said McGregor . A few trainings , including information about the impact on customer satisfaction , may help the cabin and cockpit crew make better eye contact and smile more , she said . Of course it helps to have happy employees . `` One of things we see is that when you see companies that have high internal employee satisfaction , they have high customer satisfaction as well , '' she said . Customers love technology . Now a smile does n't take care of everything . Customers also want their technology . Those who use Wi-Fi in-flight are happier ( 39 points happier ) than those who do not use it . More than one-third of customers surveyed check in online , and 15 % of those technologically savvy fliers use their smartphones or other mobile devices ( compared to 6 % two years ago ) . Passengers checking in via mobile applications are the happiest of all fliers checking into their flights , followed by passengers who check in using a mobile device , passengers who check in at an airport kiosk and those who use the main ticket counter . Baggage fees still lower satisfaction . Even attitudes toward baggage fees are beginning to soften . Although passengers are still dissatisfied with being charged for something that used to be included in the price of a plane ticket , they are n't as grumpy about it . The gap between passengers who pay for baggage and those who do not pay shrank to 63 points this year , compared with an 85 point gap last year and a 100 point gap in 2011 . Some 37 % of passengers who pay for bags agree that the fees are reasonable , compared to 28 % last year and 18 % in 2011 . `` Baggage fees are still a point of contention for people , and it 's still a 'disatisfier , ' but people are starting to accept it 's a cost to travel , '' said McGregor . To help reduce costs , J.D . Power recommends using an airline 's mobile application to check in , select seats and receive an electronic boarding pass . If you do n't have an airline credit card or frequent flier status to waive baggage fees , look for discounts when checking in online . The passenger satisfaction study is based on responses from more than 11,800 passengers who flew on a major North America airline between April 2012 and March 2013 . Overall airline rankings . Alaska Airlines and Delta Air Lines topped the traditional carrier rankings , followed by Air Canada ( 671 points ) , American Airlines ( 660 ) , United Airlines ( 641 ) and US Airways ( 630 ) . Low-cost carriers JetBlue and Southwest were followed by WestJet ( 714 ) , Frontier Airlines ( 708 ) and AirTran Ariways ( 705 ) . ( AirTran is now part of Southwest . ) Do you have anything nice or not so nice to say about North American airlines ? Please share your positive and negative thoughts in the comments section below .
JetBlue tops airline satisfaction study for ninth consecutive year . Passengers who use in-flight Wi-Fi report more satisfaction with their airline . An employee smile or two ( or more ) makes passengers even happier . Comment: