Ok, so we have a question - say you have a customer that comes and signs up and purchases one license or product - then a few days later comes back and purchases the same thing again, and then during the same month purchases 4 more licenses. Would he be charged for each of the licenses or would he be charged one time?
In MemberMouse it's possible to create products  with many types of payment options (i.e. one-time charge, free trials, paid trials, subscriptions, payment plans, etc). The answer to you question depends on the type of product being purchased.
One-Time Charge Products
If the product in question is a one-time charge product and has no recurring billing then each time the customer purchases this product they will be charged that one-time fee.
Trial and Subscription Products
If the product in question has a recurring billing component (i.e. trials leading to a subscription or straight subscription products) then you have some options available to you.
By default, each time a customer purchases a recurring billing
product it will create another subscription on their account. So if over
the course of of a few months they purchase that product 2 or more
times, they would be billed 2 or more times in accordance with each
subscriptions billing schedule. All active subscriptions will show up
and be able to be managed on the subscriptions tabs in the member
details area . The customer will also be able to see this information
and manage their subscriptions from their My Account page.If you don't want customers to be able to purchase the same
subscription multiple times you could configure MM to disallow the
purchase of duplicate subscriptions .If your products have a free trial you can restrict the purchase of
these product to one per account and specify an alternate product in the
case where someone tries to sign up for a free trial again .
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