We charge fee for calculations, offering per calculation fee, as well as monthly and annual subscriptions.
For details see "Buy Credits".
You can pay through PayPal (PayPal account or credit card).
Your payment details safety is provided by PayPal.
You can pay through bank transfer.
For payment via wire transfer, please e-mail us your account details and the wanted subscription type.
If you want to pay due some users - send me list of usernames/e-mails.