A recent survey shows in-store retail sales on Black Friday, the “busiest shopping day”, dropped from last year.

Holiday shoppers spent $11.2 billion at stores across the US this Black Friday, down 1.8% from last year, according to a Saturday report from the Chicago-based retail technology company ShopperTrak.

Those lower in-store sales figures were apparently impacted by hundreds of thousands of shoppers hitting stores on Thursday (Gray Thursday) evening after filling up on turkey and stuffing.

“Black Friday shopping continues to expand into Thanksgiving Day and will impact the way we look at all of the <<Black>> weekend results, since more shopping hours allows for more shopping visits and a smoothing of sales across all of the days,” said ShopperTrak founder Bill Martin.

Big chain outlets including Sears, Target, Toys R Us and Walmart opened their doors as early as 8 p.m. on Thanksgiving Day.

A sharp rise in online shopping likely added to the drop in spending at brick-and-mortar stores this year.

E-commerce sales rose 17.4% on Thanksgiving and 20.7% on Black Friday, compared with last year, according to a recent IBM survey.

A recent survey shows in-store retail sales on 2012 Black Friday dropped from last year

Still, ShopperTrak said Black Friday foot traffic increased 3.5% this year to more than 307.67 million store visits – a sign that more people were browsing store shelves, if not making actual purchases.

“Black Friday continues to be an important day in retail,” Bill Martin said.

“This year, though, more retailers than last year began their doorbuster deals on Thursday, Thanksgiving itself. So while foot traffic did increase on Friday, those Thursday deals attracted some of the spending that’s usually meant for Friday.”

ShopperTrak estimated that foot traffic increased the most in the Midwest, up 12.9% compared with last year.

Foot traffic in the Northeast increased the least compared with last year, up 7.6% in regions that include those hit hardest by Hurricane Sandy.

ShopperTrak, which counts sales numbers from 25,000 retail outlets across the US, had forecast that Black Friday sales would grow 3.8% this year.

A separate survey from the National Retail Federation says holiday spending on both days combined will likely rise 4% this year.

Some positive signs of spending growth have been in the news in the past few months. U.S. consumer confidence rose to 72.2 in October, its highest level since February 2008 and up from 40.9 a year ago.

Yet many consumers are still worried about the slow economic recovery, high unemployment rates and a looming fiscal cliff.