Half of people have never shopped in the Black Friday event and just half of those who expect to this year believe they will get a good deal, a poll has found.
Just three in 10 (28%) of those who have previously shopped over Black Friday weekend said they actually enjoyed it, the survey by Which? found.
Only 49% who plan to shop in the sale this year believe they will get a bargain.
Which? managing director of home and legal, Alex Neill, said: "Don't believe the hype. Which? has shown that Black Friday isn't all it's cracked up to be.
"Whether you're looking to bag a bargain online or in-store this weekend, do your research so you stand a chance of knowing whether you're getting a good deal and don't buy for the sake of buying."
The consumer group released the poll findings as it listed "essential" Black Friday shopping rights for those navigating the sales. They are:
1. Buyers have 30 days to return a faulty item to the retailer for a full refund. Some retailers may extend this over the Christmas period.
2. When it comes to unwanted purchases, most high street shops are not required to have a returns policy so a refund may not be available. Buyers should always check the store's returns policy, and any special Christmas dispensation, at the till.
Online purchases are different. Buyers who change their mind can get a full refund on non-faulty goods within 14 days of delivery.
3. The Consumer Rights Act protects shoppers when they buy digital content - apps, movies, music, games or eBooks - that is faulty.
4. It is the retailer's responsibility to deliver the goods. If an order does not arrive, turns up damaged or goes missing, speak directly to the shop where it was bought.
:: Populus surveyed 2,088 adults on November 19-20.