The serious question is do people actually use these things? Yes the standby list may be short and they may even get on an oversold flight but for every one of those there is another flight where zero standbys get on. Any guess what the next flight is in 12 hrs or maybe tomorrow or three days from now.
The revenue tickets are so cheap why bother? Pack in backpack or even pay for a checked bag when you buy the ticket and it’s still insanely cheap. Friends don’t let friends fly buddy passes. Tell your cheap ass friends to buy a ticket and enjoy the Jetblue er... Spirit experience.