For a new user: 2MB per new user.
(A new user that has not visited our site before, and must fetch application assets such as images, fonts for the first time.)
For a user that is actively using the application: 0.1 MB per user, per minute.
(Based on aggregates of usage patterns, and so will be a rough approximate. It will be more reliable to monitor how things go during a trial run.)
For a user that is playing a video: 1.4MB per user, per minute if at low quality, or 2MB per user, per minute at high quality.