Also the local eBay equivalent TradeMe gained its popularity on this network. Given somebody’s bank account number I can transfer money to their account within an hour (used to be overnight until a few years ago). There’s no reversal for this so it’s safe for the seller, and since it’s a real bank there’s no way to freeze it without a court order.
The banks being banks of course are trying to ruin this, since using the big card networks gives them free revenue.