What I like about the VM-centric design you've adopted is that 'apps' are long-running by default. Sandstorm in its current form is not great for hosting internet-facing sites.
Sandstorm tries to encourage web publishing apps to work in a way that significantly reduces resource usage and improves security. The platform will let an app publish a static web site which does not require starting up the app to serve. The platform also lets an app expose an API which starts up the app on-demand. So the app can publish a bunch of static content which includes Javascript that invokes the API when needed (e.g. when a comment is posted), which then wakes up the app to update the static content.
But, yeah, for a fully-dynamic web site served to a large number of users, Sandstorm currently isn't well-suited. It'll get there eventually, but given that other platforms (like Portal) already cover this use case pretty well, we wanted to focus on the interesting things we can do with fine-grained containers.
