> that seems more like an exaggeration than a fraud if the product does work for the most part no?

If you bought it to go to the moon, it doesn’t work as promised. If the lie was wilful, that’s honest-services fraud.

Less facetious of an example: you sell a company that makes lots of money but has a material liability on its books. The liability can’t kill the company. But you intentionally hid it from a buyer. The company still generates all those dollars. But your hiding this material fact from the purchaser is fraudulent.

Disclaimer: I am not a lawyer. None of this is legal advice.