"That Metered World will use your account's Free Regions quota so will remain available for access indefinitely." means we don't take it away after 6 hours.
This paragraph was quoted from the bottom of our Services page that provides all the details of how we bill our users. I hope you agree that I don't need to quote the entire page when referring to parts of it. Had you read that page you would have seen that we don't charge you when people on Premium accounts visit your world and that "If your account runs out of KC then everyone who isn't on a Premium Account will be prevented from visiting your Metered Worlds until you get more KC."
Joe, if you comment on the contents of some website page (in this case Kitely's Services page) then please at least do other people reading your comments the courtesy of actually reading that page first. Otherwise you start looking silly... :-)