More than 44 million Americans have a side hustle, according to an estimate from personal-finance company Bankrate based on an inaugural survey of more than 1,000 adults. Some 28% of younger millennials between the ages of 18 and 26 are the most likely to have a monthly side hustle versus 21% of older millennials, 20% of Generation Xers — roughly born between 1965 and 1980 — and 15% of baby boomers.
Domain names are the internet equivalent of real estate and, much like with homes, savvy consumers stand to make big bucks out of flipping them. Grant Sabatier, the founder of the website Millennial Money, who said he became a millionaire largely through various side hustles he developed over the years, has made more than $140,000 through domain reselling.
Read MoreUnlike flipping real estate, buying and selling domains does not require a lot of cash up front. In one case, he said he bought a web address for $40 through an auction and ended up selling it to a restaurant with the same name for $5,000. “The vast majority of domains are sold on the secondary market,” he said...
