Can I limit the number of times a discount code is used?
Absolutely - this is an amazing way to provide partners and VIPs with discount codes, but not have the code be re-used by just anybody.
When creating a discount code, set the Number Available to determine how many times this code can be used.
This is the number of orders the discount code can be applied to. If a buyer purchases 10 tickets in a single order, this will only count as one use of the discount code.
If you're looking to limit one discount code per person, check out the "Limit One Order per Email" option in the Tickets tab.