[t43562]

You could have a way to earn credits which would allow your own messages to get sent. i.e. it wouldn't be about money.

Ontop of that, I think payment isn't critical. You join the mesh because you want to use it yourself - all you need then is to limit how much power you're prepared to spend on it. What does it matter to you if 100 people use your phone or none? ....other than power.

To put it another way, I think money would introduce a commercial motive which would end up gobbling up the system like bitcoin mining.

[yetihehe]

I think that money would only be used to send messages, as a way to prevent excessive spam. There needs to be some limitation. In whatsapp it's unique number or phones. Once you send too much spam from one number, it's burned. If you have anonymous network, how do you otherwise prevent from making new accounts for sending spam? If it is invite-only network, then it's pretty small problem.

I don't think relaying messages would require that much power and as you said, "You join the mesh because you want to use it yourself".