One always can prepay with paypal.

Got to billing, then to manage payments. The one time payment option let’s us prepay $5 to $100 at a time.

I have no idea how payment works. Can I pay at any time with the credit card(s) I registered to my account? Does DO have automatic deduction? If so, when does the payment get deducted? What are the due dates for my billing periods?

@Mitch Ogaard: Credit cards are automatically billed on the first day of each month.
You can add a second credit card so if the first one fails the second one will be billed.

You can prepay using your credit card by submitting a one time PayPal payment (you do not have to register for a PayPal account).

We're also adding a lot more help documentation into each page of the control panel. The pages that have it already it will appear in the bottom right as a grayed out "?" icon. That will bring up additional information.

We have rolled out a "Pay Now" button for accounts that have been verified but currently it only supports clearing out whatever balance you have on your account and not paying extra. But you could send payment via Paypal which would be applied as a credit as some of the other users have mentioned so that you don't have to worry about having funds on the account.

Also if you don't have funds you will receive an email each time we attempt to bill the card and it fails so before there is any action taken you'll probably have 10 days worth of emails from us letting you know that payment has failed.

It would be really great to be able to have yearly plans. In addition, a management dashboard you can manage clients. Or, be able to assigned credit cards to droplets.