In the United Kingdom, Canada, Australia, New Zealand, and Trinidad and Tobago, Boxing Day is primarily known as a shopping holiday. Boxing Day sales are common, and shops often allow dramatic price reductions. For many merchants, Boxing Day has become the day of the year with the greatest revenue.

Originally Boxing day was a holiday (December 26) on which servants, tradespeople, and the poor traditionally were presented with gifts. By the 21st century it had become a day associated with shopping and sporting events. ~ Wikipedia