How did we sell cars before the Internet? Newspapers and word of mouth, that's how. Can you imagine anything more labor intensive? But then science discovered the Internet, and with it Craigslist, and BAM! People had an easy way to clear out their garages.
https://www.hagerty.com/media/buying-and-selling/craigslist-cars/
https://www.hagerty.com/media/buying-and-selling/craigslist-cars/
