Cam Fairbairn was working in restaurants when he started a side hustle — work he did on top of his regular job — making and selling his own jam. Making jam was a hobby, but he'd been encouraged by a friend to make it an extra source of income. However, he soon stopped enjoying it when his hobby became a business. He went back to focusing on his day job. But not everyone is so lucky. For some, a side hustle is not just a good way to make extra money from something you love — it's a necessity. Shonnita Leslie had big education debts to pay, so while she was working at a university during the day, her side hustle was delivering food. She needed the extra money to pay off those debts. And according to new data, Leslie is not alone. A survey by Bankrate found that more than one third of Americans have a side hustle. Among those aged between 18 and 27, it's 48%. Of the Americans with a side job, 36% use that extra money to pay for daily necessities like housing and food. And 32% said they think they'll always need a side hustle to make ends meet. "People are telling us they're side hustling because they have to, not because they want to," Ted Rossman from Bankrate told CNBC. The survey of more than 2,300 Americans also found that about 28% of people with a side hustle make at least $500 per month from their second job. Around 9% of people said they make more than $2,000.