Hi,
Just an idea:
Is it possible to set up a system where someone is able to subscribe by sending a text message to a premium rate number and that person receives a code and is able to place the code to be able to subscribe.
Some people just dont have fundds available but nearly always have credit on their phones and so, if there was a need for such a thing, could it be introduced.
I have no idea of setting up / running costs with the telecoms company but the suggested way could have a slightly increased cost to the subscriber compared to other methods to help pay for it.
Just a random thought.
Peace out