Building a profitable and market-beating portfolio doesn't happen overnight. It takes time, consistency, and patience to work toward the returns that you ultimately desire. And despite your best due diligence, not every stock you buy will be the winner you hoped for. 

This is why it is crucial to always do your research and make sure you thoroughly understand any stock before you buy it, while also making investing a habit and regularly adding to a wide variety of stocks across a diverse range of sectors. A diversified portfolio can both help you ride out the highs and lows that the market brings, while enabling you to benefit from a variety of growth stories as you work toward your long-term financial goals.

If you're looking for two smart stocks to buy and hold for at least a decade, here are two worthy contenders to consider right now.

1. Pinterest

Pinterest (PINS -1.97%) has capitalized on the impulse that many online users experience in the digital age, to scroll and search visually appealing content for long periods -- sometimes hours -- on end. With an image-and-video-centric design that appeals exactly to this kind of usage, it's no wonder that the platform has grown into an advertising powerhouse used by everyone from household name brands to mom-and-pop businesses.

Monthly active users were up 4% year-over-year and 35% on a three-year clip as of the end of 2022, while the company's ratio of monthly active users to weekly active users reached a record high figure of 61%. Meanwhile, video-focused ads remain key to management's long-term growth vision for Pinterest's future in the competitive advertisement space. In the 2022 earnings calls, CEO Bill Ready noted that:

Our supply of content is growing. Video content is up 30% quarter on quarter. We're finding more efficient ways to get engaging content on Pinterest, serve the need of our pinners you know, from inspiration to action. And importantly, while we're seeing more than 10% of our engagement is on video ... more than 30% of our revenue is on short-form video. 

While overall revenue grew 4% year-over-year in the final quarter of 2022, shopping ad revenue jumped by a mouth-watering 50% in the three-month period alone. Pinterest's 2022 revenue of $2.8 billion was up 9% from 2021, but up 150% compared to its revenue in 2019.

The company just reported its financial results for the first quarter of 2023 on April 27, and investors reacted strongly, with the stock falling about 16% on the news. The stock dipped for a few key reasons. First, while Pinterest generated revenue of $603 million in the quarter, up 5% from the year-ago period, and ended the period with 463 million monthly active users, a healthy 7% year-over-year spike, the current weaknesses in ad spending given the macro environment hit the bottom line hard. The company is also investing heavily in the growth of its platform right now, even as ad rates are declining. It reported adjusted EBITDA of $27 million for the three-month period, but a net loss of $209 million. 

On Pinterest's platform, clickable ads blend in easily with inspiration-inducing photos and videos, creating a seamless experience for users that can carry them from searching for an idea without an end goal in mind to actually making a purchase. This is a powerful competitive advantage that Pinterest can leverage over the long term. Yes, the current ad spend environment is causing a deceleration in growth. This isn't just true for Pinterest of course, but for any business built around advertising dollars. However, given the long-term growth potential of this platform, its beaten-down share price may be  one that investors may want to take note of in the current market environment.

2. Apple

Apple (AAPL 1.30%) has long been known for its dominance of the smartphone market, a space in which it accounts for more than 24% of all sales globally. In the first quarter of the company's fiscal 2022, $66 billion of Apple's $117 billion total net sales were derived from iPhone sales. 

While sales of these hardware products remain Apple's bread and butter, another segment is quickly catching up. The company's services segment, which is comprised largely of subscription-based offerings like Apple Music, is growing rapidly. This recurring revenue business contributed $21 billion of Apple's total net sales in the first-quarter period, more than sales from its Mac, iPad, or Wearables/Home/Accessories segments. 

Apple is also looking to the future as it seeks to build out its competitive advantage in other lucrative markets, including the financial services space. The company launched its own buy now, pay later product last year. And it just launched an interest-bearing savings account in partnership with Goldman Sachs. The account currently boasts an annual percentage yield of 4.15%, while the national average is only around 0.4%.

The company is also looking to other high-octane industries on which to build out its growth story. While it still has a modest footprint in the advertising space, it's estimated that Apple could be generating more than $10 billion in ad revenue alone by the end of next year. Then, there's it's much anticipated virtual reality headset, which by some reports could be out as early as June of this year.

Apple is a business that has stood the test of time in countless economic storms. The diversity of its business offerings, its continued expansion into new areas, and its market-leading products should continue to drive profound growth over the next decade, even if consumer spending slows in the short term. Bear in mind, this is a business that has seen its operating cash flow and profits rise by respective amounts of 51% and 74% in the past three years alone.