What I can't work out is why you'd pay a tenner a month for it! If you're already paying for an ISP and spending about a tenner a month, then add another tenner a month and you've already got the price of a broadband connection which you can use 24/7 with unlimited download and a much, much higher connection speed.
It's a great idea and I'm sure it works, but it whiffs of snake oil if you ask me...