Re: Grow the cloud, ignore the rest
Yes, not only is it more difficult to get out but at least with an onsite system you can create your own tool to migrate data. You can also do this where your cloud acts just as a data store. However once your only access to the application is a web front end you may find that it is impossible to retrieve the underlying data (some of which you may be required to retain for x years for compliance purposes).
Therefore you may find that legally it is impossible to stop using your cloud service and the only way to get out of it is to phoenix the company and start again - quite a dramatic move.