When businesses are small and in their growth phase, it's not uncommon to see year-over-year rates of revenue growth in excess of 50%. Of course, such a pace isn't sustainable, and eventually, companies transition to maturity, in which expanding profits is more important than adding to the top line alone. 

Over the course of years, many businesses start to lose steam as their markets become saturated by competitors or otherwise fully penetrated. But with some companies, regular growth continues practically indefinitely, and that means investors can see the value of their shares rise year after year. Here are two such stocks that are perfect for those who are willing to play the long game.

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1. McKesson

McKesson (MCK 0.47%) is a Warren Buffett stock, and (unsurprisingly) it's also a proven and relatively safe way to compound your wealth. 

The medical supply distributor can grow sustainably because its ability to grow at all is grounded in the orders it takes from its customers in healthcare. As long as demand for healthcare rises over time, McKesson will have exposure to upside too, and that's how it managed to profitably grow its quarterly revenue by 118.6% in the last 10 years, topping $70.4 billion. In the same period, its quarterly net income rose by 154.5%, reaching over $1 billion in the third quarter of its fiscal 2023, and there's even more growth on the way quite soon.

In addition to distributing its usual fare across the globe, McKesson will be building out its oncology and biopharma services segments, tapping into a rising demand for new oncology medicines and laboratory supply needs in biopharma. While it's always possible that an economic calamity might reduce the demand for some of its wares, there's little chance that healthcare systems are going to suddenly not have enough money to keep buying bandages and critical medicines, so the business is quite robust as it grows.

It's also quite the avid dividend hiker, with its payout expanding by 170% in the last 10 years. Its forward yield of 0.6% won't make you too rich anytime soon, but there's also practically zero chance that it'll get cut, considering that its payout ratio is a scant 9.2% of its earnings. So, if you're willing to buy this stock and hold it for years and years, it's likely to pay off -- and if the next five years are anything like the last five, you might even beat the market with an investment too.

2. Costco

Costco Wholesale (COST 0.55%) is one of the best stocks for investors seeking steady and fairly safe growth for as long as they're willing to hold it. 

In case you're not familiar, the wholesaler makes money by selling memberships that grant entry to any of its 848 warehouses across the U.S. and the world, where subscribers can purchase all manner of dirt-cheap groceries, alcohol, electronics, gasoline, prescription drugs, and even car parts. Because the company opts to sell its goods at close to their cost, customers keep coming back again and again because they can't get a better deal elsewhere. And because its 123 million subscribers each pay an annual fee, in the last 12 months, it raked in $4.3 billion in membership fees alone, accounting for most of its $6 billion in trailing-12-month (TTM) net income.

With so many customers and more than one way of generating money from catering to them, it's no surprise that it's growing steadily, albeit at a slower pace today than in years past. Here's how Costco rates in terms of its average growth rate of quarterly revenue and net income over the last 20 years:

As you can see, this company keeps stacking more sales and more earnings like there's no tomorrow for years and years on end. It's the kind of reliable expansion that Warren Buffett likes, which is probably why he and his partner Charlie Munger held it for more than 20 years before selling it in 2020 for a tidy profit.

What's more, Costco pays a dividend that currently yields 0.7%, and it also disburses special dividends on occasion. That's right: Once every few years, you'll get paid a bonus from just holding this stock. And if getting paid to do essentially nothing isn't a nice profit, not much else is.