ComScore found that shoppers started the holiday season strong in November but a dip in consumer confidence hurt early December sales.
Shoppers picked up spending in the final days of the holiday season.
That includes a 76 per cent increase on what retailers called "Free Shipping Day" on Dec. 17 and 36 per cent more on Christmas day itself.
ComScore says the online sales growth rate was essentially on a par with last year's, but it missed expectations for a 16 per cent increase.
