Costco (NASDAQ:COST) keeps humming along as if nothing has changed in the retail world. The company has been immune to the so-called "retail apocalypse" that has hurt many of its rivals. It has also shown that the warehouse-club model can retain customers, even when low prices are available elsewhere, where consumers don't have to pay a membership fee.

In its most recent quarter, the chain saw net sales jump 8%, to $28.22 billion from $26.15 billion during the third quarter of last year. Through three quarters, or 36 weeks, in the chain's fiscal 2017, net sales were up 6%, to $84.82 billion from $80.34 billion last year.

On top of that, same-store sales were strong for the quarter. They grew by 6% in the United States, where the retailer has most of its stores, and 2% in Canada, as well as 4% in the rest of the world. That worked out to a 5% increase systemwide for the quarter and 3% same-store growth year to date.

CFO Richard Galanti celebrated the results during a conference call with analysts, which was transcribed by Seeking Alpha (registration required). In his remarks, he offered some insight into how the company sees the results.

A Costco store with a crowded parking lot.

Costco continues to draw customers even in the face of strong online competition. Image source: Costco.

Earnings are strong

In Q3, Costco saw its earnings per share (EPS) climb from $1.25 a share to $1.59 a share, a $0.35 increase. Part of that increase, $0.19 per share, or $82 million, came from an income tax benefit in connection with the $7-a-share special cash dividend that the company declared on April 25. Even without that special benefit, the numbers are trending strong, according to Galanti.

"Our overall bottom line in Q3 benefited earnings by $0.14 a share," he said. "By comparison and I believe in Q1 and Q2 the numbers were up $0.01 or $0.02 less than that per share, but still significant as we are still in the first year of the program change."

Memberships are up

With Costco raising its membership prices on June 1, it seemed possible the chain would experience a big jump in memberships. It seemed, however, that the $5-per-year increase in the cost of a Gold Star membership and $10 jump in Executive Membership cost were not major drivers. The warehouse club added members, but the increases were in line with recent quarters.

"Total card holders, came in at the end of the quarter 88.9 million, up from 88.1 million at the end of the second quarter," Galanti said. "Paid Executive Memberships stood at 18.3 million, and increased during the 12-weeks of 345,000 new Executive Membership or about 29,000 a week increase in the quarter."

Executive Members now account for about 38% of Costco's membership base and 70% of its sales in the countries where the program is offered. After the price increase, an Executive Membership will cost $120, up from $110, but will now offer 2% cash-back rewards of up to $1,000 a year, up from $750.

The new credit card is killing it

Since Costco switched its rewards credit card from American Express to Visa managed by CitiGroup on June 20, 2016, the results have been strong. At the time of the switch, the warehouse club had 11.4 million co-branded cards representing 7.4 million accounts that were transferred to CitiGroup.

"As of Q3 end, we now have about 1.5 million new approved member accounts, which represents about 2 million new cards since the last June 20th and that 1.5 million that represents about 290,000 additional accounts over the past 12 weeks since Q2," Galanti said. In addition, people with the new card are spending more than people who were part of the previous program.

Daniel Kline has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Costco Wholesale and Visa. The Motley Fool recommends American Express. The Motley Fool has a disclosure policy.