Adobe Analytics forecasts that online sales in November and December will grow at an average of 10% - the weakest pace in at least eight years. And that would be less than a third of last year's record jump, when people staying indoors amid the health crisis opted to let their fingers do the shopping.

Threatening to strain holiday commerce: product shortages due to supply chain issues, higher prices, and uncertainties tied to the health crisis. Adobe Digital Insights says the lack of clarity around what items could run out of stock and when is making it hard to determine whether product shortages could drive consumers to shop more online or in stores.

Bargain hunters may also have a harder time this year. To cope with potential inventory shortfalls, retailers are offering fewer discounts and encouraging people to shop early.

Adobe said consumers will face higher prices due to skyrocketing commodity and transportation expenses. They are expected to pay 9% more between Thanksgiving and Cyber Monday this year.