Sales totaled $52.4 billion, and the average shopper spent $398.62 over the holiday weekend, up from $365.34 a year earlier, the Washington-based trade group said in a statement today, citing a survey conducted by BIGresearch. More than a third of that -- an average of $150.53 -- was spent online.

Many retailers opened on Thanksgiving this year to lock in sales from consumers still leery about spending amid 9 percent unemployment, a sluggish housing market and slower third-quarter economic growth than previously estimated. The number of people shopping during the Thanksgiving Day weekend rose to a record 226 million, up from 212 million last year, the NRF said.

Toys “R” Us, for example, opened at 9 p.m. on Thanksgiving and started importuning shoppers a month before with circulars and emails, the earliest ever according to chief executive officer Gerald Storch. Deals included half off board games, with titles such as Candyland selling for $5.

More than half of shoppers bought clothing, the most popular category, followed by electronics.

The number of people shopping online and at stores on Thanksgiving Day jumped to 28.7 million from 22.2 million last year. About a quarter of all shoppers visited stores by midnight of Black Friday, up from just 3.3 percent two years ago.

“Consumers are clearly demonstrating their desire to spend this holiday season, but are far from throwing caution to the wind when it comes to how much they will spend on gifts,” said Phil Rist, executive vice president at BIGresearch. “Retailers will have to stick to an aggressive holiday promotion schedule to keep consumers interested.”

Black Friday, so named because it was traditionally the day many retailers became profitable, is expected to be the busiest shopping day this year, a status it had ceded for some years to the Saturday before Christmas.

Holiday sales may rise 2.8 percent this year, or about half of last year’s 5.2 percent gain, according to the NRF.