Christmas has come and gone, but Wayne Best says holiday retail sales still have some life in them.

Best, the chief economist at Visa USA, pointed to gift cards as a sales stimulus. He said that in recent history, card redemptions pump up sales volume in the week following Christmas. 

He told CNBC’s Michelle Caruso-Cabrera on "Morning Call" that lukewarm holiday sales can be attributed to “the cautious consumer” – buyers who emerged from their shells to take part in a “very strong spending” surge on Dec. 22 and Dec. 23. Best counsels patience, saying the full impact of the purchasing and redemption of gift cards won’t be known until January.

The economist cited drug-store chains as the second strongest growth segment within retail, ranking between home-furnishing sellers and electronic stores. But the segment’s growth wasn’t due to shampoo or acetaminophen sales; Best says firms like Walgreen and Rite Aid were “heavy sellers” of personal entertainment devices, such as Apple Computer’s iPods and Nintendo’s Wii game consoles.