Costco (NASDAQ:COST) has been a retail force. The warehouse club saw net sales rise 5% year over year in the fourth quarter to $41.4 billion, and climb by 9.7% to $126.2 billion in 2018. In addition, same-store sales rose by 9.5% for both the quarter and the full year, while digital sales were up 26.2% in Q4 and 32.2% for the year.

The membership-based retailer has proven that it's not going to be a victim of the retail apocalypse. It has clearly shown that its customers remain loyal and that they have become even more willing to shop at the warehouse club at a time when other retailers are struggling.

CFO Richard Galanti laid out where the company stands during its Q4 earnings call on Oct. 4. He had a lot of positive news for investors during a call that also offered some forecasts.

The exterior of a Costco with a crowded parking lot.

Costco has seen its sales steadily rise. Image source: Costco.

1. Income is going up

Earnings per share came in at $2.36, up 13.5% compared with the same quarter last year. Given that the quarter had 17 weeks in 2017 versus 16 this year, the increase was actually 20%, Galanti said.

Income from membership, which drives about 75% of the company's profits, was up 2.3% for the quarter. Most of that increase came from the company's $5 to $10 increase in annual fees that took effect on June 1, 2017, at the chain's U.S. and Canada locations.

2. Renewals remain strong

Renewal rates rose in Q4, Galanti said.

In the U.S. and Canada, the renewal rate came in at 90.4%, up from 90.1% at the end of Q3. Globally, the renewal rate landed at 87.9%, an increase from 87.5% at the end of the previous quarter.

"In terms of cardholders, we ended the year with 94.3 million cardholders, up from 93 million at Q3 end," Galanti said. "... Also at Q4 end, paid executive memberships stood at 19.3 million. That's an increase of 229,000 executive members during the 16 weeks, or about a 14,000 increase per week."

3. Steady growth continues

Costco isn't a chain that opens huge numbers of stores. Instead, it steadily grows by adding a few warehouses each quarter. That continued in fiscal 2018, when the chain added 21 new locations, 13 in the U.S.

"For '19, we expect to open 20 plus in the low 20s net new warehouses," Galanti said. "About three-quarters will be in the United States and about a quarter international."

4. Digital is strong

"This past fiscal year, our site-traffic conversion rates in orders all improved year over year," Galanti said. "Online grocery, both our dry grocery two-day delivery as well as our same-day fresh delivery -- the latter through Instacart and others like Shipped -- are growing nicely but still a very small part of our company's sales."

To continue that growth, he noted that Costco plans to keep improving its online merchandise selection. He added that the company plans to keep revising its omnichannel capabilities, specifically by offering more items for sale online that can be picked up in-store.

Very little to worry about

While Galanti noted that tariffs might cause some pricing issues, he made it clear that Costco has plans to handle them. He was generally upbeat and made it clear that the warehouse club should continue to move steadily forward. That's very easy to believe because Costco has been a steady performer that has shown it's not going to be hurt by market trends or changing shopping behavior.

Daniel B. Kline has no position in any of the stocks mentioned. The Motley Fool recommends Costco Wholesale. The Motley Fool has a disclosure policy.