While some holiday shoppers jumped the gun on Black Friday and eagerly headed out to retailers Thursday evening, early consumer trends for the four-day holiday shopping spurt are indicating that the real surge in sales this Thanksgiving weekend is coming from online shopping.

Software firm Adobe tracked 100 million visits to about 4,500 retail websites Thursday and found that more than $1 billion has been spent online so far -- and that numbers are projected to hit $1.7 billion by the end of the evening.

“Thanksgiving Day online sales continue to trend ahead of expectation as we head into the evening hours, when mobile shopping comes back into the mix,” Tamara Gaffney, principal

 analyst at Adobe Digital Index told TechCrunch

IBM also kept track of online sales throughout Thanksgiving Day, publishing real-time numbers that showed the average value per order has been $142.55 as of 6 p.m. EST. The value was up from $125.25 in 2014 and $132 in 2013. Mobile shopping, too, saw heavy traffic early Thursday, with an estimated 28 percent of all Thanksgiving Day sales being made on mobile devices, according to IBM.

Black Friday People work during Black Friday deals week at an Amazon fulfillment centre in Madrid, Nov. 24, 2015. Photo: Reuters/Andrea Comas

But while online sales have soared, in-store shopping has been lackluster so far. It was expected that shoppers would be more cautious with their spending this year due to lagging job growth and stagnant wages — the National Retail Federation expected holiday sales to rise just 3.7 percent this year, down from last year’s growth rate of 4.1 percent.

“It’s still early, and from what we are seeing so far the crowds are good, but not great,” Craig Johnson, president of Customer Growth Partners, told Reuters. The retail consultancy studies customer traffic across the United States.

More and more retailers sought to take advantage of the Thanksgiving Day sales this year. Macy’s opened shop at 6 p.m. local time, Toys R Us at 5 p.m., JC Penney at 3 p.m. and RadioShack at 8 a.m., while retail giants Walmart, Target and Best Buy opened at 5 p.m. and 6 p.m. But some, including T.J. Maxx, Marshall's and HomeGoods, opted to remain closed Thursday and wait for the traditional Black Friday sales, even airing commercials declaring Thanksgiving should stay special — out of the line of fire of the intense sales pressure that come with the holiday season.

Up to 20 percent of holiday shopping is thought to be done over Thanksgiving weekend, analysts said. The four-day shopping spree will serve as a litmus test for retailers deciding whether to lower prices or change promotions in the upcoming weeks.