Amazon (AMZN -0.01%) is one of the world's great companies. Its business is so legendary that it's easy to forget that Amazon has existed as a public company for just a couple of decades.

Today, let's have a look at how much Amazon has grown since entering the stock market in 1997, and how much investors would have gained in both dollars and shares if they had gotten in on the ground floor with this American corporate titan.

Amazon's growth since 1997

Amazon debuted via an initial public offering (IPO) on May 15, 1997. Shares were priced at $18. By the end of that first day of trading, they were changing hands for more than $23. The company's market capitalization stood at $560 million.

Needless to say, anyone who invested on that first day and held on has racked up big gains. For example, an investor who bought a single share for $18 would now have over $50,000 worth of stock.

Moreover, they'd own quite a few more shares of Amazon. The company has split its shares four times since its IPO:

• 2-for-1 split in June 1998
• 3-for-1 split in January 1999
• 2-for-1 split in September 1999
• 20-for-1 split in June 2022

As a result, our hypothetical investor would no longer have one share of Amazon, but 240. They would be worth nearly $54,000 at today's share prices. Not bad for an $18 investment, 28 years ago.

Is Amazon still a buy now?

Since their debut, Amazon shares have generated a tremendous 32.3% compound annual return -- far outpacing the S&P 500's 9.3% performance over the same period.

Thanks to Amazon's diversified business streams, vigorous growth, and excellent management, I believe it remains a strong long-term buy today.