The way I read understand the Django documentation, the 'django.contrib.staticfiles' app collects static content from apps, put them in the folder specified by STATIC_ROOT. After that it is able to serve from there.
But this works even when the specified folder is non-existing or empty (if 'manage.py collectstatic' has not been called).
How?
The Django test server still serves the files, e.g. the admin media: http://localhost:8000/static/admin/css/base.css
(Django 1.3.1)