In case of any service, the user needs to be able to move on. To me, that is the ultimate antidote to most of the ails services afflict, like lock-in, altering the offer, raising the price above a reasonable limit, and so on. If the user cannot, or can hardly move on, the pain is big. If the user is willing to adapt, services are an actual good deal. They can be enjoyed while they last, and the world is full of other wonders ready to discover, when they fail.