The social media market has grown like a weed over the past decade. Facebook (NASDAQ: FB), the world's largest social network, grew its monthly active users (MAUs) from 197 million in the first quarter of 2009 to 2.9 billion in the second quarter of 2021. The explosive growth of Facebook and other social networks permanently changed how people interact with each other, how advertisers target consumers, and how news spreads across the internet. The global social media market could still expand at a CAGR of 25.4% between 2019 and 2026, according to Research and Markets, as the industry's leading platforms attract even more users and advertisers. Let's examine three companies that will profit from the market's long-term expansion. Image source: Getty Images 1. Facebook Facebook also owns Instagram, Messenger, and WhatsApp. The number of monthly active people (MAP) who use at least one of those apps increased 12% year over year to 3.51 billion last quarter. Facebook generates most of its revenue from targeted ads, which enable advertisers to display ads based on a user's personal data, preferences, and social networking interactions. It also owns a small but rapidly growing VR division called Oculus, which sells VR headsets and VR content. Facebook's apps already reach nearly half of the world's population, but it plans to gradually merge its social networking and VR businesses into a "metaverse" that blurs the lines between the physical and digital worlds. That evolution could enable Facebook's users to interact with each other within virtual spaces beyond the confines of PCs and mobile devices. Facebook remains a popular target for privacy advocates and regulators, but it's still growing rapidly. Its revenue and earnings rose 22% and 57%, respectively, last year, even as it was pilloried for the unmonitored circulation of fake news and hate speech on its platform throughout the election cycle. Analysts expect Facebook's revenue and earnings to grow 39% and 40%, respectively, this year, as its advertising business faces fewer pandemic-related headwinds. Those are impressive growth rates for a stock that trades at 23 times forward earnings. 2. Snap Facebook tried to buy Snap (NYSE: SNAP), the parent company of Snapchat, for $3 billion in 2013. Snap walked away, and it's now worth nearly $113 billion and serves 293 million daily active users (DAUs). Image source: Getty Images. Snap continues to grow for three reasons: It's the top social networking platform for teens, it encourages users to create and share their own AR lenses, and it locks in its users with an expanding ecosystem of original videos and in-app games. Snap is also expanding into the "social shopping" market with camera-based visual searches, shoppable ads, and integrated e-commerce features. That expansion, which mirrors Instagram's introduction of shoppable ads, could reduce Snap's dependence on traditional ads. Snap's revenue surged 46% last year, and its adjusted EBITDA turned positive as it narrowed its losses. During its investor day earlier this year, Snap predicted it could grow its revenue by about 50% annually over the next few years as it gained more DAUs, sold higher-value video ads, expanded its AR ecosystem, and launched more e-commerce features. Snap's stock isn't cheap, trading at 27 times this year's sales, but that premium could be easily justified by its ambitious long-term goals. 3. Pinterest Pinterest (NYSE: PINS), which served 454 million MAUs last quarter, caught the market's eye last year for two main reasons. First, it gained tens of millions of new users throughout the pandemic, since its virtual pinboards were a natural platform for sharing cooking, crafts, and other stay-at-home ideas. Second, it was well-insulated from the fake news and hate speech controversies that plagued Facebook and Twitter. Most people joined Pinterest to share hobbies instead of their political views. Like Snap, Pinterest also aspires to become a social shopping platform. Many advertisers already sell products through its shoppable pins, and some major retailers like IKEA have already uploaded their entire catalogs to Pinterest's boards. Pinterest also partnered with Shopify last year to help smaller online merchants upload their catalogs to Pinterest. Pinterest's revenue grew 48% last year as its adjusted net income increased nearly 16 times. Analysts expect its revenue and adjusted earnings to rise 55% and 150%, respectively, this year -- which are the growth rates investors want to see for a stock that trades at a lofty 39 times forward earnings. Pinterest's stock stumbled last month after it posted a sequential decline in MAUs in the second quarter, which it mainly attributed to relaxed COVID-19 restrictions and reopening trends. It could face tougher year-over-year comparisons for a few more quarters, but I personally believe its long-term growth potential as a social networking (and shopping) platform remains bright. 10 stocks we like better than PinterestWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now… and Pinterest wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of August 9, 2021 Randi Zuckerberg, a former director of market development and spokeswoman for Facebook and sister to its CEO, Mark Zuckerberg, is a member of The Motley Fool's board of directors. Leo Sun owns shares of Pinterest and Snap Inc. The Motley Fool owns shares of and recommends Facebook, Pinterest, Shopify, and Twitter. The Motley Fool recommends the following options: long January 2023 $1,140 calls on Shopify and short January 2023 $1,160 calls on Shopify. The Motley Fool has a disclosure policy.Source