It seems to me that there could exist a paypal-like system for micropayments. Maybe there already is and I don't know about it? Getting a critical mass would be necessary, a bit of a chicken-and-egg problem. If there was a service that went something like this:

- pay a flat fee of $x to deposit any amount up to $y

- pay nothing to transfer <$1 to another user (really just shifting numbers in a spreadsheet)

- pay $x to withdraw up to $y

You are incentivized to deposit more to make it worthwhile, fees don't eat into your per transaction revenue, and you're incentivized to wait for at least $y to cash out for maximum benefit. The company can invest that $ in the meantime and earn a low yield on a money market.

I'm sure if it were that easy it would already be done, but it makes sense to me.