Sal Aiello and Monica Powers built their lucrative side hustle in four days — and spent less than $200 to get it off the ground.

At first, they started running their side hustle ideas past ChatGPT, using the generative artificial intelligence chatbot as a starting point for market research. Then, they realized they knew how to ask ChatGPT the exact right questions to get useful answers — and other people probably didn't.

Aiello is a longtime CTO for tech startups, and Powers is a product designer who currently runs a strategic design and branding company called Mascot. In March, they decided to create an AI-powered research tool: Fill out a form about your idea, and the tool would input your answers to ChatGPT in a maximally helpful way.

"Maybe we can sell this," Aiello, 36, recalls thinking.

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Days later, they launched DimeADozen for "want-repreneurs" to pressure-test their business ideas. It charges $39 for a comprehensive report, and compiles results in a fraction of the time it typically takes traditional analytics agencies or search engines.

In roughly seven months, DimeADozen — split evenly between Aiello and Powers — brought in more than $66,000, according to documents reviewed by CNBC Make It. With the exception of $150 for the web domain and $35 on hosting and a database, nearly all of it was profit, Aiello says.

Last month, they struck a deal to sell the side hustle for $150,000 to Felipe Arosemena and Danielle de Corneille, a husband-and-wife duo — one is a software engineer, the other a product designer — who want to make DimeADozen their full-time jobs, says Aiello.

Aeillo and Powers plan to keep working roughly five hours per week on it as company advisors.

"It really does print money," Aiello says.

AI side hustle

Powers and Aiello met last year at a virtual startup founder meetup event, run by Silicon Valley startup accelerator Y Combinator, and quickly started working together in their off-hours. They currently have three other side hustles, with plans to start more.

None have yet reached the heights of DimeADozen, which is — by Aiello's account — the first AI research tool built specifically to test out business ideas. It plugs the information it receives into hundreds of pre-written ChatGPT prompts, and organizes the answers into 50-page reports on the hypothetical company's potential investors, customers and competitors.

You could do the same thing on Google. It would take a lot longer and the results would be less reliable, Aeillo says.

"There's no reason you can't do 1,000 Google searches and get the same results," he says. "[But] it's a no-brainer to lean on somebody [to do it faster]."

Powers and Aiello also used their prompt engineering skills — a technique for asking chatbots targeted questions to get more precise results — to minimize the risk of AI hallucinations, Aiello says. That's when chatbots spit out information that sounds appropriate but is actually completely false.

DimeADozen can't promise to eliminate them entirely, but "we mitigate hallucinations by tweaking the prompt parameters and by being very strict in our prompting," says Aiello. "It took weeks of back and forth to make sure we got the response we expected out."

In his dream world, the tool might one day get acquired by cloud-based software giant Salesforce "or something silly like that," he says. "The bigger vision is: It becomes a ubiquitous tool to run a business through to validate and learn about it."

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