User blog comment:Jimeee/Elder Scrolls Online will be subscription based/@comment-16501991-20130825200307/@comment-3124449-20130826031531

I think that the only acceptable subscription method would be paying for actual time. So, say you buy a card for 100 hours, you can play the game for a total of 100 hours before having to buy more time. You would only be charged for the time you are actually playing, not the time that you're sleeping/working/eating/etc.