An early start to the US holiday shopping season boosted US retailers as customers came with their families and loaded up carts last night.

Stores noted that later shoppers seemed more focused on sale items.

In a departure from the norm, stores like Target opened hours before midnight last night to try to capture a bigger piece of the retail pie.

The move seemed to bring out a different type of shopper than the usual one who grabs the "Black Friday" deals, analysts said.

The US National Retail Federation expects sales during the holiday season to rise 4.1% this year, below last year's 5.6% increase. That made a retailer's strategy important as they battled each other, rather than seeing a growing pie.

The federation said 147 million people would shop from Friday until Sunday, when deals are at their most eye-catching - down from 152 million the same weekend last year.

The stakes are high for US retailers, who can earn more than one-third of their annual sales and 40-50% of their profits during the holiday season, which generally starts with "Black Friday," the time when some retailer traditionally turned a profit for the year.

According to a Reuters/Ipsos poll, two-thirds of shoppers were planning to spend the same amount of money as last year or were unsure about plans, while 21% intended to spend less, and 11% planned to spend more.

Younger people generally said they felt comfortable spending money, those who are retired or close to it seemed to be more cautious.

While the shift to earlier openings was criticised by store employees and traditionalists because it pulled people away from families on the US Thanksgiving holiday, many shoppers welcomed the chance to shop before midnight or in the early morning hours.

Some US workers used the day to send a message. OUR Walmart - a coalition of current and former Wal-Mart staff seeking better wages, benefits and working conditions - targeted "Black Friday" for action across the country after staging protests outside stores for months.