"This year for the first time, a lot of stores are getting on board with Black Friday deals," CBC's Briar Stewart reported from London's Oxford Street shopping area, where people were lined up to get into stores.
"Police … in a suburb of London tweeted that if you are shoving someone to the floor on Black Friday to get 20 pounds [about $36 Cdn] off a coffeemaker, it still constitutes assault," she said.
Elsewhere in the U.K., scenes were less civil in Manchester, with several people arrested, Stewart said.
Police were urging shoppers to calm down.
Online retailer Amazon is believed to have introduced the concept to the U.K. four years ago, with more businesses joining every year since. In its online survey of 10,000 U.K. shoppers, Verdict Research found 47 per cent of the U.K. shoppers plan to participate in the event.
In the U.S., some activists called for a boycott on Black Friday shopping to protest the Ferguson, Mo., decision not to prosecute police officer Darren Wilson in the shooting of Michael Brown, but there was little sign of it having much effect, CBC Radio's James Murray reported.
"If the backlash intimidated shoppers, it wasn't showing here in St. Louis, where buyers walked past National Guard troops in military vehicles to get to the deals," he said.
Even earlier start
With racial tensions rising in Ferguson, some people have campaigned to remove the "Black" from Black Friday. Some radio advertisements referred just to "Friday," Murray said, "perhaps bowing to a growing public campaign to re-name one of the biggest shopping days of the year."
Some U.S. chains remained open on Thanksgiving Day Thursday to give shoppers an even earlier start.
At a Kmart in Denver, some 100 shoppers were ready to begin a day of shopping when doors opened at 6 a.m. local time Thursday. Another 75 showed up at a Kmart in Birmingham, Alabama.
In the Chicago suburb of Naperville, Illinois, the parking lot of a Wal-Mart store was full roughly 30 minutes before Thanksgiving deals started at 6 p.m., including $199 iPad minis.
Macy's said more than 15,000 people were lined up outside its flagship location in New York City's Herald Square when the doors opened at 6 p.m.
Kmart, for its part, is defending its decision to stay open on Thanksgiving, saying it has done so for 23 years, well ahead of the new trend.
Best Buy's plan to open its stores at 5 p.m. local time on the eve of Black Friday was embraced by shoppers who responded by pitching tents to wait for the actual opening in locations like Seattle.
Working during the holidays has in fact become a common occurrence in the United States. According to a just-released Allstate/National Journal Heartland Monitor Poll, one in four workers expects to work on Thanksgiving, Christmas Day or New Year's Day this year.
In downtown Toronto, the Eaton Centre mall opened at 6 a.m. ET, though there were few early shoppers evident. at 7 a.m.
The U.S. Black Friday shopping event remains an unquestionably upbeat event for retailers.
"A lot of people spend a lot of money on Black Friday," NBC reporter Jay Gray told CBC News on Friday morning from the Mall of America in Bloomington, Minn.
"First of all, people who shop on Black Friday expect to spend $418 per person, up from recent years — great news for retailers, great for the economy, too."
The National Retail Federation forecasts holiday sales will grow 4.1 per cent to $616.9 billion — the highest increase since 2011.
The holiday shopping season is a make-or-break time for many retailers, which can get as much as 20 per cent of their annual sales during the time. Already, retailers have resorted to steep discounting to lure shoppers.