With Christmas shopping season in full swing, an increasing number of retailers are using flash sales, which offer heavy discounts but typically last only a few hours.
More than £360,000 a minute is expected to be spent this week on what has become known as 'Black Friday'.
ITV News reporter Rebecca Barry has found the sales are already under way:
Charities, protest movements and even Nasa have been launching spin-offs to the consumer hysteria that has become known as Black Friday.
After all the consumerism of Black Friday news a new charitable campaign online hopes to get people back into the spirit of Christmas.
The complex mix of marketing, merchandising and psychology that sees shoppers parting with £360,000 a minute in the UK's shops.