We recommend using voucher codes so you can track conversions, but you can also run campaigns without vouchers.
Personalized vouchers are unique per recipient and allow you to track individual transactions. If you want to use personalized vouchers, you need to upload a CSV file with at least as many unique vouchers as your total number of recipients.
This is what a voucher list looks like:
Non-personalized vouchers are assigned to a design, and so used by more than one recipient. If you are A/B testing the product you are adding vouchers to, you will be able to assign one voucher code per visual variation. All the recipients that receive that visual variation will use the same voucher.