I personally think that it is a good idea. If the service is prepaid, it is more likely to be used. If you have to 'pay by the drink' you may be more likely to put it off. I liken it to supercharging. We think of it as free. In reality, it is prepaid at time of purchase. Because of that perception, people don't think twice about using them. If we got charged every time we used one, I think it likely that they would be used a little less. Others will disagree. YMMV. :wink: