Online sales may not be the saving grace retailers were hoping for.
According to fresh data from Adobe's Digital Index, a spike in digital revenues on Thanksgiving Day wasn't enough to make up for a sluggish start to the holiday shopping season.
Sales were also tempered on Black Friday morning, as higher levels of out-of-stock merchandise contributed to slower-than-expected growth. Still, online sales continue to hit record highs.
"People are pushing their shopping habits into Thanksgiving Day, but not necessarily keeping enough gas in their tank to keep going," said Tamara Gaffney, principal research analyst at Adobe Digital Index.
According to the software company, online sales increased by 25 percent on Thanksgiving Day to $1.73 billion versus last year. Thursday's digital sales exceeded estimates for 18 percent growth.
Black Friday sales, however, are so far lagging the firm's expectations. According to Gaffney, online revenues as of 11 a.m. were up 15 percent — 3 to 4 percent lower than expected. Adobe now expects Black Friday to generate $2.6 billion in total online sales, slightly lower than its original forecast for $2.7 billion.
"What's happening every year to us is that we kind of underestimate Thanksgiving Day and overestimate Black Friday," she said.
According to separate data from ChannelAdvisor, Amazon's Thanksgiving Day sales grew 29 percent compared with last year, indicating it's stealing share from traditional retailers.
Amazon's sales growth continued to outpace that of traditional retailers on Black Friday, with ChannelAdvisor's midday report saying they grew nearly 20 percent over the prior year.
Gaffney attributed Thanksgiving Day's outperformance to robust mobile sales. Whereas the firm was expecting mobile to account for every 29 cents on the dollar that day, it ended up accounting for 37 cents.
Traffic from retailers' email marketing was a huge boon to traffic, increasing 25 percent.
"People have gotten very used to receiving those promotional emails in the very early hours," Gaffney said.
Overall, online sales are still a bit lower than expected, Gaffney said. As of Tuesday, digital revenue rose by 8.5 percent — lower than the firm's forecast for 11 percent growth over the season.
But she added there is plenty of time for online sales to make up ground.
"The largest shopping days are all from now to the end of the year," she said.