The money you put on your account covers the letters you send to him, not the other way around. For him to write back, all he needs is a postage stamp on his end. He writes a physical letter, addresses it to InmateAid's office in Florida, and mails it the old-fashioned way. That stamp is the only cost on his side.
When his letter arrives at InmateAid's office, it gets scanned and posted to your account dashboard. You retrieve it for $1.49. So the return letter system has a small cost to you when you access it, but nothing additional comes out of your pre-funded letter balance.
The reason most people use the service is privacy. When he writes back to InmateAid rather than to your home address, your personal address never circulates inside the facility. Prison mail gets handled by a lot of hands, and having your home address in that environment is something many people reasonably want to avoid. The InmateAid address keeps that information out of circulation entirely.
Thank you for trying AMP!
You got lucky! We have no ad to show to you!