Spot checks on the ground showed there were fewer shoppers this year as retail chains started offering discounts earlier than usual to make up for a shorter holiday season this year.

Shoppers also worried that tariffs imposed by President Donald Trump on Chinese imports would make their holiday shopping more expensive, though many large retailers had not raised prices to protect margins.

Fewer people lined up outside stores as Black Friday shopping kicked off, suggesting early discounts offered by retail chains and a surge in online buying may have taken the shine off America's biggest shopping day.

"There were definitely some concerns about prices due to what we see in the news about the trade war but I haven't seen the impact yet, so I am planning to spend about the same this year as I have in the past," said Jay Smith, 28, who was shopping at a Macy's in Pentagon City to buy clothes and toys for her family.

"I think there were some good deals but overall the discounts are similar to what we have seen in the past," Smith said.

While store traffic still remains an important indicator, a lot of shopping during Thanksgiving and Black Friday now happens online. Adobe Analytics, which measures transactions from 80 of the top 100 U.S. online retailers, estimates $7.5 billion in sales for Black Friday online, a growth of over 20.5% year-over-year.

Online sales on Thanksgiving Day alone jumped 17% to $4.1 billion in the United States, according to data from Salesforce. Global online revenue rose 24% to $20 billion.

Companies including Walmart, Target, Costco and Best Buy have bulked up their online presence, deliveries and fast in-store pickups to attract customers.

While Black Friday still matters, its relevance is fading as the holiday shopping season now begins the week before Halloween and stretches to Christmas Eve with retailers offering deep discounts throughout the season.

The condensed shopping season this year accelerated early promotions and spending. Retailers have six fewer days to make sales between Thanksgiving and Christmas Day this year.