Once you've applied as a reseller you will be able to create licenses for your customers and resell them on a fly. Once per month you have to pay for them via your License Account. You can check how to apply as a reseller here: http://emagicone.com/affiliate-reseller-program/
You have to pay for the licenses during the next month till the 25th. Have a look at this example:
You applied as a reseller for Store Manager for Magento. You received 10 licenses. During September (last month) you have sold to your customers 5 licenses for Store Manager for Magento Professional Edition. Till the 25th of October (during the next month) you have to pay the bill for the licenses via RegNow (PayPal, CreditCard).
5 licenses*499 USD - 30%= $2495 - 30% = 1746.5 USD
You earn - 748.5 USD
So you have 55 days to pay for the licenses if you have sold them on the first of September and 26 days to pay for the licenses if you have sold them on the 29th of September. If the licenses are not payed they will be disabled.
Proceed through few steps to complete your payment:
1. Sign in http://license.emagicone.com and go to the page with the licenses that were created for your customers.
2. Enable the check-boxes next to the licenses that you have to pay for and proceed to checkout
3. You will see the invoice with the list of licenses and their totals
On this stage you will see the redeemed total. Check carefully all details and proceed to checkout.
4. On the Checkout page specify your billing information and proceed
Once you fill in all required fields and place your order, you will see the confirmation page and those licenses that were created manually will be marked as paid
5. Check the original customer's licenses. Same licenses will be marked as paid at your reseller account.
Note: The price of licenses you have to pay for will be calculated considering your resellers discount.