I don't necessarily mean that the business would have to go to a fully-paid model, just that they will have to find some other way of adding value to their prod

I don't necessarily mean that the business would have to go to a fully-paid model, just that they will have to find some other way of adding value to their product, be it support, training, or add-on features or services. If this type of business model doesn't match with what you want to be doing, then maybe open sourcing your product isn't the right move for you.