NEW YORK – If shoppers don't show up in stores soon, more "70 percent off" sale signs will.

After a promising start to the holiday shopping season over the four-day Thanksgiving weekend, sales have slowed, according to an analysis of data done for The Associated Press by sales tracker ShopperTrak. Worries about weak U.S. job growth and other concerns are likely to blame for Americans spending less.

That puts pressure on J.C. Penney, Macy's and other stores, which had been offering fewer discounts this season than they did last year, to step up promotions to lure shoppers like Ron Antonette from Long Beach, Calif.