A free market is a market without barriers to entry, in which anyone is free to make offers, receive offers, select trading partners and trade with them as they see fit.
You and I have never experienced a free market for good and services – we’ve only experienced marketplaces which are distorted by aggregators.
p.s. It’s worth noting that a ‘free market’ does not mean the freedom to do anything at all (e.g. to defraud someone else). Free markets are supported by market rules and government regulations which provide safety to participants and one of the key challenges for offerbots is to provide freedom and safety for participants.