I'm not sure if this is allowed.
But, if it is allowed.

Owing to my increased recent domestic travel, I'm willing to buy jetblue promotion codes for domestic travel, that is at least worth over a $100. Please let me know of the value of the code through a message. Do not give it away in the first message. We shall talk about how much you want for it.

You can let me know of the code once we have a deal. I will make the payment through paypal, or a direct bank transfer once I am able to successfully apply the coupon/promotion code.

I hope this is fair enough owing to the fact that many people might claim that they have a code which might not work when I try to apply it.