What if your website provides long term service and you want to sell it? Example: Your website provides service for 2-3 years and on the way you want to sell it to a new owner. Can you somehow insure yourself that new owner will still provide service to the customers till its expires. Can you ask this from a new owner? lets say the service is absolutly automatic
Well it sounds somewhat like hosting - and people sell those all the time. Usually the new owner will want to provide support to the customers to hopefully have them stay on in the future (so they can make money then)
You could just pay the new owner for the amount that your clients have left on their contracts. Make sure that the new owner provides good services. I would also suggest giving your clients the option to opt out of the contract.