The web is a truly GLOBAL medium. Take a look at visitor stats. There are probaby some countries on there that you may not even have heard of!
Some countries are deemed to be higher risk than others. If you know which countries your (credit card) processor scrubs, you can and should send surfers to a an international tour/join version of your site (s) using
our hosted
http://www.webpinaccess.com/?layout=blank template.
Select Brazil, Russia, India, China etc to see what surfers from there will see

And don't worry, the only people hogging your bandwidth will be paying ones
Since the payouts available from such billing is not suited to monthly subscriptions, simply give them less time.
If you have compelling content, the chances are good that the surfer will come back again and pay you this way - not least since you gave him the option to commit to a subscription in the first place.
Useful EXTRA money...
