Many people have commented about the need for many people to keep their diary even though they may not have a credit card or bank account and that their parents would then have to pay for the account, something they wouldn't want to do if they didn't want their parents to even know they kept a diary.
The subscription mechanism WILL be voluntary, with some possible sweetners. But you will NOT be forced to subscribe to continue using the system and you will not lose any functionality that currently exists. The subscription will not be required from anyone. We would hope that those who CAN pay, WILL pay and will help support those who can't. A bit like a Social Security payment in any community :)
To answer Damselita's question about keeping track of who recommended who, we won't need to. The system will do that for us :) At least, we'll make sure it does because you're right, we don't need the extra work!
But please feel free to keep sending your feedback, so far its been very positive, and useful.
Steve.