What is the act of making exaggerated claims to achieve a sale called?

The act of making exaggerated claims to achieve a sale is referred to as puffing. This term is commonly used in sales and marketing contexts wherein a salesperson expresses a subjective opinion or boasts about the qualities of a product to make it appear more appealing to potential buyers. Puffing is generally understood not to be misleading or fraudulent because it does not claim any factual basis; instead, it represents an exaggerated sales pitch meant to influence a buyer's perception.

In this context, it is distinct from terms like procuring cause, which relates to the chain of events that leads to a real estate transaction, or bluffing, which often implies deceit in the absence of factual assertions. Marketing, while encompassing a broad array of strategies including puffing, does not specifically denote the exaggerated claims aspect. Hence, puffing is the most precise term to describe the practice highlighted in the question.