A GMRS license allows anyone in your family to operate under the umbrella of your license. For that alone its a valuable tool for expo use.
I believe the Amateur radio rules don't allow anyone but a licensed HAM to operate an amateur band radio. Handing the mic to the wife or sending the kids out with a portable are not technically legal.
My wife has also got her ticket. HAM clubs setup demonstration tables all over the U.S. So as to build interest in the hobby. Hams, refer to handing the mic over to a non-licensed person as third party operator, followed by the stations call sign.
Kids are welcome to become lic. Ham Operators as well. It is sorta like driving a car, know the rules, understand button, frequencies, bandwidth, antenna propagation, how a signal travels which freq. operates best in mountainous versus desert terrain.
I am an always have been dyslexic at math but, I studied the test over and over till I became haunted at night. I even read several books just because I thought they were interesting how signals travel through our atmosphere. I even learned how communications signals travel through our earths rock formations. Example Submarine communications.
But, as it is folks, where else can ah common guy spend his time, a wee bit of money, so as to GAIN access to a Nationwide Mulltimillion dollar communications system?
Another reason, Civil strife. Every community that suffers major disruptions even loss of celluar some HAM dude shows up in his COMM RV, sets up a field station then others post themselves at emergency centers whalla, instant communications net. It is an opportunity to assist your community in time of need.
Digital:
The newest is GPS location tracking technology. Simular equiped radios can display grid cordinance whenever transmission occures.
I don't own such a radio but it is offered.
Next would be Satillite Communications. Don't know much about that either. But what I have seen it would be an alternative to one whom enjoys spending a goodly amount of time in the backcountry. I'm certain the wife or significant other's would appreciate such availability.
Next would be texting, television etc etc. Its a hobby like ExPo... How much yah wanna spend....