Imagine we have several requests from clients for custom Force.com apps. Surely we can build those and get paid once, but for continuity, we (and our client) like to have a licensing model where they pay us for every user/month. Note that we want the model such that the client only needs to pay us and does not need to already have Force.com / CRM licenses. We then pass a part of the revenue to Salesforce.
Salesforce offers ISV Partners the possibility to create such apps (Force.com embedded), however, as far as I know, you need to publish these apps to the AppExchange while, in contrast, for our clients we only want them to be able to install their app, and nobody else. I.e. we do not want an AppExchange listing.
Is this possible, and if so, how?