The greater CASK of the e-jet V 737 means the e-jet is a lot more critical on selling a full aeroplane(or achieving high yield) in order to keep a lid on the greater than 737 costs. Perhaps it isn't fair to compare the two but the balance sheet certainly will. If one doesn't generate greater profit yet costs more to run what is the purpose? Only the accountants know the answer........I hope the e-jet is as good as some report.