The US Christmas shopping season got under way on Friday, with shoppers braving the cold to look for bargains.
A number of negative economic effects may hit spending
On what is traditionally known as "Black Friday", many shops open their doors at midnight or before dawn.
Laptops, televisions, toys and clothes are among the most popular items, as shoppers hunted out discounts.
And despite a gloomy prognosis many big name stores reported bigger crowds for the early morning bargains than they did a year ago.
The National Retail Federation predicts combined November and December holiday sales will grow by 4%, the slowest since 2001, when sales were up 1.3%.
The cautious outlook has been caused by a falling US housing market, a credit crunch, and rising food and fuel costs.
"Retailers knew they had to offer promotions enticing enough to get shoppers out of bed on a chilly day, and they delivered," said Tracy Mullin, chief executive of the National Retail Federation.
"Though retailers are anticipating a challenging holiday season, they are encouraged by the enthusiasm that their Black Friday sales generated."
The Thanksgiving weekend accounts for about 10% of all holiday sales.
Black Friday, one of the busiest shopping days of the year, used to be the day when a lot of retailers turned profits - literally going into the black - for the whole year.
This year stores started offering discounts and extended their working hours several weeks ago, expecting a difficult time ahead.
The most recent official data from the Commerce Department showed that retail sales rose by just 0.2% in October, compared with September's 0.7% gain.
Shoppers braved freezing conditions
At the same time, some of America's largest retail firms, such as Macy's, Limited Brands, JC Penny and Nordstrom, all saw same-store sales fall last month.
The downturn in the housing market has centred on record levels of mortgage defaults in the so-called sub-prime sector, which specialises in higher risk loans to people with poor credit histories, or those on lower incomes.
Most of the main US banks have subsequently lost billions of dollars after having to write-off their exposure to this bad debt.
The crisis has made the banks much less willing to lend among themselves or to other borrowers, both reducing and pushing up the price of available credit.
America's central bank, the Federal Reserve, has confirmed that economic growth is now slowing.
Earlier this week it cut its forecast for 2008's economic growth to a range of 1.8% to 2.5%. Previously it has predicted growth of between 2.5% and 2.75% for next year.