Bottom line is still that any manual work (cashing a check, mailing one, cash-paying a bill at a bank...) must be one or two orders of magnitude more expensive than wiring.

I'm not sure what the costs are for wiring as it is usually packaged. I pay $30-40/year for Internet bank w unlimited wiring including p2p through phone number (yes guaranteed/negotiated transfer to the babysitter!). Meanwhile cash-paying a bill or cashing a check is probably $10 a pop, simply because banks are trying very very hard to get rid of two things: cash and staff. that makes a lot of sense from a business perspective.