Once upon a time a sale was a real life event, complete with door-busting prices and crazed shoppers. Many of us can still recall the Boxing Day sales as something that was covered by the news, often revealing people going to drastic lengths to buy at a discounted price.
Source: https://www.northernstar.com.au/news/ready-set-sale-make-the-most-of-online-bargains/3777909/