Top 10 Best Side Hustles That Became Empires

Under Armour started when Kevin Plank sewed moisture-wicking shirts in his grandmother's basement while playing college football, selling them from his car trunk to teammates in 1996. Plank's targeting of athletes led to $17,000 in sales the first year and $10 million by 2000, a trajectory comparable to the average apparel startup's 10-year path compressed into 4. By 2014, Under Armour reached $3 billion in annual revenue, proving that basement-sewn side hustles can challenge industry giants like Nike.

Craigslist became a classifieds empire by gutting the newspaper industry, starting as a 1995 email list from Craig Newmark's personal hobby. The site grew organically to over 80 million monthly users in the U.S. by 2023, generating an estimated $1 billion in annual revenue with fewer than 50 employees. Its free postings in most categories disrupted traditional classifieds, which charged up to $50 per ad in major papers. The platform's simplicity and lack of venture capital funding allowed it to dominate without external pressure, a stark contrast to the high-burn startups on this list.

Yankee Candle started from a high school side hustle in 1969 when Michael Kittredge melted crayons to create a Christmas gift for his mother, which neighbors wanted to buy. The company grew to $1.75 billion in sales by 2022, with over 500 retail stores and a dominant 35% share of the U.S. candle market. The brand's seasonal collections, selling over 200 million candles annually, turned a homemade gift into a global empire.

Airbnb transformed home-sharing into a $100 billion empire after Brian Chesky and Joe Gebbia rented air mattresses in their San Francisco apartment during a 2008 design conference. The platform now lists over 7 million properties globally and generated $8.4 billion in revenue in 2022, growing 40% faster than the traditional hotel industry. Its user base exploded because it undercut hotels by an average of 30% per night, while offering unique stays impossible for chains. The company's pandemic recovery, with bookings surging 50% in 2021, proved its resilience over physical retail ventures like Yankee Candle.

Dell Technologies turned a dorm-room PC upgrade business into a $90 billion technology giant, with Michael Dell selling custom computers from his University of Texas room in 1984. The direct-to-consumer model cut out retailers, reducing costs by 20% compared to rivals like IBM, and fueled revenue growth to $5 million in its first year. By 2023, Dell held a 16% share of the global PC market, shipping over 50 million units annually.

Ben Francis started screen-printing gym T-shirts from his parents' garage in Birmingham while working as a Pizza Hut delivery driver, building a $1.3 billion fitness apparel brand by age 28.

Ben Chestnut and Dan Kurzius built an email marketing tool as a side project for their web design agency in 2001, bootstrapping it for 20 years before selling to Intuit for $12 billion.