American Express is finding that even for a provider of credit cards to the affluent, it pays to focus on the highest of high rollers.

The company recently shifted marketing dollars to its refreshed Platinum card, which carries an $895 annual fee, and away from no-fee cash back cards, CEO Stephen Squeri told analysts Friday after the company reported fourth-quarter results.

Doing that helps to boost overall spending levels as high-end consumers continue to thrive, a tactic that leads to both rising fee revenue from premium cards and lower loan defaults, executives said.

“We have the ability … to be really flexible with our marketing investments, and we saw a tremendous demand for premium products, particularly the Platinum card,” Squeri said.

“The overall portfolio is slowly getting more premium [as] the Platinum portfolio is growing at a very fast pace,” he added.

AmEx’s strategy shift is the latest example of the so-called “K-shaped” U.S. economy playing out, in which wealthy consumers continue to spend freely while others rein in their expenses. Data from the card company shows that demand for high-end products and luxury experiences is accelerating, while purchases in more basic categories rises at a slower pace.

Spending at luxury retailers surged 15% in the quarter, business and first-class airfare purchases rose 9%, and luxury hotel spending was up 12%, CFO Christophe Le Caillec told CNBC in an interview.

Meanwhile, spending at airlines and lodging more generally was up 3% and 5%, respectively, during the quarter, showing that the richest cardmembers are driving results.

AmEx said Friday that new card accounts hit 2.9 million at year-end, a decline from the third quarter and the lowest figure in the past five quarters, as the company focused on its more profitable card products.

“We are incrementally worried that the Platinum Card refresh isn’t generating much traction,” said BTIG analysts led by Vincent Caintic, citing new competition from other card issuers and consumer weariness over high fees and cumbersome perks.

While the company doesn’t disclose its total number of cardmembers, including for the Platinum card, Squeri told analysts Friday that “all of the metrics that we look at speaks to the fact that this was a wildly successful product launch.”

Still, shares of AmEx were down about 3.5% in midday trading after the company’s results and guidance disappointed some.

Earnings per share of $3.53 were a penny below the consensus estimate, according to LSEG.

That was due in part to higher-than-expected expenses, at $14.5 billion, driven by the costs of the Platinum refresh, the company said.

“If there is a rub, perhaps it is that 4Q clearly shows the cost of the Platinum refresh, but doesn’t show a corresponding bump on new accounts,” wrote Truist analyst Brian Foran in a research note.