From a technical standpoint, it doesn't make sense. Why wouldn't you want to tie the membership to something else i.e.: user, login, contact?
The way Kentico manages subscriptions is they are tied directly to a user/login account. So you'd need to override the checkout process to it doesn't require this. And then tell the client they can manage the subscriptions manually in Kentico OR create some front end ability to allow the user to manage it.