I said the handling and queuing. That is indeed where the Gateways are.

Please *READ*.

The transmission costs are ultimately nil.

The costs buy *AND* run them have come down by orders magnitude.

Think back to pagers gateways... one of those... cost a few million dollars for a 64 channel, 120 phone line system, just to get the messages onto the network.

Nowadays the effective cost (based on numbers of message being sent and bandied around as costs for gateways) has dropped to about 0.005% of the cost per message handling from 1999.