Tech giant Alphabet (GOOGL -1.97%) (GOOG -1.96%) had a rough 2022. Brands cut advertising budgets as consumer spending slowed in response to scorching inflation, putting pressure on the company's top line. That headwind was intensified by unfavorable foreign exchange rates driven by the strengthening of the U.S. dollar.

Alphabet reported disappointing financial results over the past year. Revenue increased by just 18% and free cash flow declined by 5%. That performance marks a material deterioration from the prior year when revenue climbed 39% and free cash flow soared 93%. As a result, many investors have unloaded the stock, and Alphabet's share price currently sits 41% below its all-time high set in November 2021.

For context, Alphabet has never seen its share price fall that sharply at any other point in the past decade. But investors can put a positive spin on that drawdown by viewing the current situation as a once-in-a-decade buying opportunity.

Here is what investors should know about this FAANG stock.

How Alphabet makes money

Alphabet breaks its business into two segments: Other Bets and Google. Other Bets is a collection of unprofitable moonshot ventures like autonomous driving company Waymo and artificial intelligence research company DeepMind. Google is a collection of content platforms and cloud products -- YouTube, Google Search, Google Play, and Google Cloud -- and it primarily generates revenue through advertising and cloud services.

The investment thesis for Alphabet

Google positioned itself as the gateway to the internet. Chrome holds 65% market share among web browsers, Google Search holds 92% market share among search engines, and YouTube recently surpassed Netflix as the most popular streaming service as measured by viewing time. Those content platforms, along with the consumer data they generate, have made Google the cornerstone of the digital advertising industry.

In fact, the company currently collects about 28% of all digital ad dollars worldwide, and while competitors like Amazon are gaining ground, Google's expertise in artificial intelligence and search algorithms should keep it ahead of the pack for the foreseeable future. That means shareholders can expect solid growth from Alphabet's ad business in the coming years, as global digital ad spend is expected to increase by 9% annually to $1.3 trillion by 2030, according to Precedence Research.

Meanwhile, Google is also gaining momentum in cloud computing. As of the third quarter, Google Cloud Platform held an 11% market share in cloud infrastructure and platform services (CIPS), up from 10% in the prior year. Google still trails Amazon and Microsoft by a wide margin, but the company is improving its CIPS capabilities and growing revenue more quickly than other major cloud vendors, according to IT research company Gartner. That trend bodes well for Alphabet. Cloud computing spend is expected to grow at 16% annually to reach $1.6 trillion by 2030, according to Grand View Research.

In a nutshell, Alphabet has a strong position in two large and growing markets. The challenging economic climate may continue to weigh on its financial results in the near term, but temporary headwinds don't change the long-term investment thesis. Alphabet is well positioned to deliver double-digit growth on the top and bottom lines through the end of the decade, and that could certainly translate into market-beating returns for patient shareholders, especially since the stock is trading at a discount to historical valuations.

The stock trades at a reasonable price

Currently, Alphabet stock trades at 4.1 times sales, a shade higher than its five-year low of 3.9 times sales and well below the five-year average of 6.4 times sales. Similarly, shares trade at 17.5 times earnings, a bargain compared to the five-year average of 31.8 times earnings. Those valuations look reasonable for a business with a great shot at double-digit sales and earnings growth through the end of the decade.

Wall Street seems to agree. At the moment, 45 of the 49 analysts covering Alphabet have a "buy" or "outperform" rating on the stock, while the remaining 4 analysts have a "hold" rating on the stock. Not a single analyst recommends selling the stock at its current price.

For all those reasons, investors should take advantage of this once-in-a-decade opportunity and buy a few shares of this growth stock.