An inch off seat pitch can go a long way
I am sure you have heard many times the story of the American Airlines manager that saved his airline millions of dollars but just removing an olive from in-flight menus..it's a good example to illustrate how, when you are flying millions of people every year, even a small optimizing change can compound really quickly.
I don't know if the olive story is true or not, but it came to my mind when I read this very similar story about Southwest Airlines.
As the story goes, the American low cost carrier might have achieved hundreds of dollars of extra revenue by reducing seat pitch by just a single inch, as this allowed the airline to add up to six additional seats per flight!
I haven't stopped to check whether these numbers really add up or not but I hope the article doesn't give European airline managers new ideas...!