Costco Wholesale ( COST ) reported its monthly sales data earlier this week and surprised its shareholders with a massive dividend increase, adding to its long streak of annual dividend hikes.

On Wednesday, Costco released its March sales results, revealing a 9.4% increase from the prior year to $23.48 billion. Included in the report was news of a 13.7% increase to its quarterly dividend.

The warehouse giant will now pay a dividend of $1.16 per share each quarter, equating to an annualized dividend of $4.64 per share. This gives its stock a yield of about 0.6% based on today's share price. The next dividend is payable on May 10 to shareholders of record at the close of business on April 26.

Why should I invest in dividend stocks?

While Costco's yield does not turn heads, it has shown a strong dedication to growing its dividend, which is good news for income investors. The membership warehouse company has now raised its dividend every year since it initiated its payout in 2004, which means the increase it just announced marks the 20th consecutive year it has done so. 

Costco is now just five years out from becoming a Dividend Aristocrat, a distinguished group of companies in the S&P 500 that have raised their payouts annually for at least 25 years in a row.

There are several reasons investors seek out these top dividend stocks. "Shares in companies that raise their payouts like clockwork decade after decade can produce superior total returns (price change plus dividends) over the long run, even if they sport apparently ho-hum yields to begin with," writes Dan Burrows, senior investing writer at Kiplinger, in his feature on Wall Street's best dividend stocks for dependable dividend growth. 

Additionally, companies that raise their dividends year in and year out demonstrate both financial resilience and a commitment to returning cash to shareholders, Burrows adds.

What's more, once Costco becomes a Dividend Aristocrat, investors will see it added to some of the best dividend growth ETFs (exchange-traded funds), such as the ProShares S&P 500 Dividend Aristocrats ETF ( NOBL ) , which currently yields 2%.

Costco's expanding offerings

Costco is the world's third-largest retailer and currently operates 876 warehouses across the U.S., Puerto Rico, Canada, Mexico, Japan, the U.K., Korea, Australia, Taiwan, China, Spain, France, Iceland, New Zealand and Sweden. It also operates e-commerce sites in the U.S., Canada, the U.K., Mexico, Korea, Taiwan, Japan and Australia.

You can get just about anything at Costco these days. Earlier this month, the warehouse giant announced that members in all 50 states can now get prescriptions for weight-loss drugs, including Ozempic and Wegovy, through its partnership with Sesame.

Costco has also been selling gold bars for nearly a year and recently added silver coins to its offerings – and it's been selling a lot. Wells Fargo ( WFC ) estimates that Costco sells between $100 million and $200 million of gold every month, according to CNBC.