High consumer confidence could drive shoppers out of the house and into brick-and-mortar stores this holiday season, former longtime department store executive Jan Rogers Kniffen told CNBC on Monday.

In turn, that could put a dent in Amazon's fourth-quarter sales, he added.

"When the consumer is happy or feels good, they're more likely to be in the stores and doing things experiential because it's fun," Kniffen said on "Power Lunch."

Calling Amazon "efficient" and "good at what they do," Kniffen also argued that "Amazon is not fun."

The e-commerce giant, however, is "still taking over," even as traditional retailers like Walmart, Macy's, and Nordstrom continue to beef up their online presence, he said.

"If the economy slows, you'll see Amazon take back over," said Kniffen, CEO of his eponymous consultancy that gives advice on retail trends to mutual funds, hedge funds, and private equity firms.

In an attempt to stimulate sales and compete with other giants like Walmart, Amazon announced Monday that it will offer free shipping for all purchases that can delivered by Christmas.

Kniffen predicts another solid increase in total holiday sales in 2018, buoyed by "record low" unemployment and rising wages.

"I think we're going to see 5.5 percent, just like we did last year, unless something dramatic happens," he said. "And I don't expect to see anything dramatic happen."

In 2017, the National Retail Federation said total sales for November and December were $691.9 billion.