We came across something similar to this when we were researching credit unions and pay-day lending. One of the reasons that people on benefits here can't access cheaper fuel bills is that they have difficulty planning their finances on a monthly basis when given a fortnightly lump of money. I can't remember the exact figures - I think it worked out as something like £5 a month they were losing. Which when you multiply it up for thousands of people or significant stretches of time is fairly significant - more or less what some people are getting into debt over, multiplied by a year, for people borrowing money to cover Christmas for instance.