If you noticed Black Friday lines appeared a bit thinner this year, there's a good reason.

According to The Daily Mail, research firm ShopperTrak reports early figures indicate Black Friday sales at retail stores fell by more than a billion dollars this year, down from $11.6 to $10.4 billion.

In addition, Thanksgiving Day sales tumbled from $2 billion in 2014 to $1.8 billion this year. ShopperTrak comprised the figures partly based on data composed from its 1,200 members. Their figures don't include e-commerce.

As much as anything, the changing way of holiday shopping appears driven by a rise in the number of on-line shoppers, with more consumers now zeroing in on targeted deals via their smartphones, tablets and computers.

That trend has made it easier for retailers to offer bargains long before Thanksgiving, limiting the impact of Black Friday specials.

For weeks now, Adobe reports on-line retailers have been hitting consumers with emails heralding their planned discounts, contributing to on-line sales increasing by more than 14 percent on Black Friday compared to last year.

Overall, email promotions drove 25 percent more sales this season compared to last. It's enough to have IHS director of consumer economics Chris Christopher predicting that holiday season e-commerce sales will jump 11.7 percent this year to about $95 billion, up from last year's 10.9 percent gain.

In all, IHS predicts about $1 in every $7 in holiday shopping sales will occur on-line this year, fueled by price slashing offers billed as Black Friday deals that now actually start as early as Halloween.

"Consumers have shifted and started earlier," said ShopperTak co-founder Bill Martin.

Indeed, research shows that even though December remains the month in which consumers spend the most, November has now emerged as the month in which most Americans are doing the bulk of their holiday shopping.