Of course, at $16/1st minute + $8/add'l minute (+ taxes) you wouldn't expect much usage.
I don't get it why they didn't try a $.50 a minute pricing and see if it stimulated usage -- the variable costs of the service can't be that high (all the cost, phones plus transmitters), were sunk.
You can't use cellphones in the air. And those airphones allowed a F/A to provide vital information on 9/11. No more.