No, your tickets are not guaranteed to sell. Your ticket(s) will only sell if they are purchased by another participant.
If your tickets are set to ship, and do not sell before they ship, your tickets will be sent to you in the mail. After they have shipped your tickets can no longer be sold through STEP but you are welcome to sell them in person to another participant.
If your tickets are being held at Will Call, and do not sell before STEP closes, you can still claim them in person at the Box Office. Shipping will begin in mid-June. Only tickets that have not shipped or are set for pick up at Will Call can be resold through STEP. If you want to have the option to sell your tickets through STEP after fulfillment begins, you can email participantsupport@burningman.org to change your delivery method to Will Call; however, this change can only be made before your order has shipped.
Please note: if you have multiple tickets in your order, and you only wish to sell part of your order through STEP, you will need to change the method of delivery for your entire order to Will Call as we are not able to split the method of delivery for different tickets on the same order.