It's pretty darn simple.
Think coffee. First, you decide how thirsty you are before ordering. The barista then fills your chosen cup size and "voila" that's all you pay for. No more. No less.
Still thirsty? No problem! Just rock on up to the counter and order another.
Technically, we've set up our techie bits and pieces in a number of campus-like locations. For you it literally just means you can plugin and jump online at any one of them!