said by rocca:
Some ISP's do have 'fair use' clauses that enable termination if the usage is x times the average, but personally I'd prefer being upfront with it. If we say 'unlimited' then it has to be that IMHO, now it could say something like 'unlimited, no overage charges and full speed until you hit x GB and then y speed', but again being upfront about it. Just telling people after the fact that they've used more than some number I had in my head and therefore I'm cancelling their service isn't too cool with me.
And that is why we appreciate Start so much! I know I've experienced the kind of surprise that you've mentioned with other service providers and it is not a pleasant feeling.