More than a third of Americans had a side hustle at the start of the year and 21 percent more planned to start one in 2021. With so many profitable side hustle ideas out there, it's no surprise that people are finding ways to make extra money.

One of the most lucrative side hustles, however, is the good old-fashioned copywriting. Freelance copywriters make an average of $55,000 per year. That's pretty good for a full-time salary, and outstanding for a side hustle.