The key is that it's the same cost to you to serve one on the net as it is to service 5 million. The marginal cost is so low that even reaching a few hundred extra customers could make the difference for the right company. I expect our client to reach thousands of extra customers over the next year. Those numbers are not insignificant. Mosaic will run on a simple machine and it's easy to use.
Lynx requires even less hardware.
I can log in to a shell account from my old AT or C-64 and run Lynx. I think we need to remember that there are solutions here now, and it's not difficult to support them. The urgency part doesn't quite work for me. That's the old mass marketing approach. With a simple additional feature, the net could provide marketers immediate identification of the recipient.