Shoppers are going to malls and stores with a purpose, knowing what and where they want to buy, according to ShopperTrak. They window-shop ahead of time online, the firm said, so retailers should be adopting strategies to seize the opportunity, both before and once the shopper is in-store with the intent to buy.
So the big question that has retailers' white-knuckling it in the final days leading up to Christmas is: are those sales lost for good, or will shoppers hit the stores to finish up this week?
Retailers like having shoppers in stores because it provides a chance to persuade them to make unplanned purchases. The more harried and rushed shoppers feel, the less likely they are to veer from their shopping list.
(Read more: Pssst, Santa! This is what kids want this holiday)
Still, some of the busiest shopping days of the season remain, said ShopperTrak. It predicts four of the top 10 sales days occur between now and Christmas Day.
Retailers are banking on it.
Some shoppers may have other plans, however.
According to the National Retail Federation's latest holiday survey, conducted by Prosper Insights & Analytics, nearly half of holiday shoppers indicate that they plan to do the rest of their holiday shopping online, the highest percentage in the survey's 11-year history.
As of Dec. 9, 32 million holiday shoppers had not even started shopping, the retail industry trade group said.
"Last-minute shoppers don't have quite the breathing room they did last year, when there were four full weekends, but we shouldn't underestimate procrastinators," said Pam Goodfellow, Prosper's director of consumer insights.
—By CNBC's Courtney Reagan. Follow her on Twitter