I actually think that pressures from customers increases somewhat when they are dealing with an ongoing fee which they see hitting their accounts on a monthly b

I actually think that pressures from customers increases somewhat when they are dealing with an ongoing fee which they see hitting their accounts on a monthly basis. Every time I see it there is a question of, "how is this software working for me? Do I still need it?" ... Not so much the case with perpetual licensing until it is time to (potentially) upgrade.