( CNN ) -- Frequent flyer programs are meant to breed passenger loyalty . The logic goes that if travelers can earn free tickets and preferential treatment by flying one airline or alliance , they will . A new study shows that this is n't always the case . A poll of 1,005 British citizens conducted by Collinson Latitude found that 40 % of those signed up to airline loyalty schemes never redeem miles , which , one would imagine , slightly defeats the purpose . Given the many seeming limitations associated with them -- blackout dates , minimum spends , expiry dates -- it 's not surprising . `` It 's ironic that what is meant to be a key benefit for travelers becomes a key frustration quite quickly , '' says James Berry , product director for Collinson Latitude . Jay Sorensen , the president of IdeaWorksCompany , which consults airlines on how to build and improve their loyalty schemes , says he does n't find the study surprising . `` The UK is a bit of an enigma in the market , as their three largest airlines do n't encourage people to sign up to their programs , '' he says . British Airways ' scheme , titled the Executive Club , is almost exclusively geared towards business travelers , he says , while neither Ryan Air nor EasyJet have designated programs . Is that seat free ? Still , if a good loyalty scheme is rated on the ease of acquiring a reward seat , the British carriers are n't the only ones letting customers down . IdeaWorksCompany recently conducted research as part of the Switchfly Reward Seat Availability Survey . Throughout March , they made 7,560 queries for free seats on 25 leading airlines , and tallied the percentages that were available . Air Berlin , GOL and Southwest tied for top spot , each able to accommodate queries 100 % of the time . Delta and US Airways tied for last place , with only 36.5 % of requests resulting in a potential booking . Read more : Airbus rolls out new A350 XWB . The discrepancy , Sorensen says , simply comes down to the fact that some airlines think making reward seats available is good business practice , while others just do n't see it as a priority . Arguably , some airlines are more interested in selling reward miles to third parties , such as banks , who can distribute the miles as rewards to their own customers . The practice is a multi-billion dollar earner for many carriers . `` They love cashing the checks from the banks , they just hate to give up those seats , '' quips Sorensen . More bang for your buck . Another major grievance for those polled by Collinson Latitude was the lack of affordability of reward seats , with 60 % complaining it takes too long to earn enough miles to get anything of value . Gary Leff , the cofounder of frequent flyer community milepoint.com , and a consultant on the Freddie Awards , which recognizes airlines with the best loyalty schemes , notes that some carriers have hidden value that one might not realize from simply skimming their policy page online . Infographic : What we spend on business travel . `` Air France-KLM are particularly good , '' he says ( the airline recently won four Freddie 's for their Flying Blue program ) . `` They have frequent promotions that allow members to redeem international awards at just half the usual miles . '' The best part is that Air France-KLM are partnered with Delta , meaning if a member of Delta 's SkyMiles program ca n't find the reward seat they want at the price they want , they could always try using those miles to book with Air France . Does it make you loyal ? As only 60 % of those polled seem to make use of their frequent flyer program , it 's understandable to question whether these schemes succeed in building allegiance to a brand . Sorensen says sadly , it 's a difficult prospect to measure . `` If we had an airline that would turn their program off , we would have empirical evidence one way or another , but no one has done that , because these programs are a weapon no one wants to be without . ''
Recent survey found 40 % of passengers never redeem loyalty miles . Comment: Air France-KLM seen as one of the best , partnering with Delta .