Can't you just use a subscription model? Give the customer a certain time (say, three months or one year) and start charging after that. This way, they won't fe

Can't you just use a subscription model? Give the customer a certain time (say, three months or one year) and start charging after that. This way, they won't feel as if you are taking something away from them when you pull the plug, and the service may actually be able to go on with this extra revenue alone.