The phase of the product life cycle in which healthy profits usually begin to appear is the stage.

The answer is the growth stage. The introduction stage, when a company is launching a new product is normally the most expensive for a company launching a new product. In that stage, expenses are high but market size and sales are low. The growth stage is were sales increase, and company profits grow as the economies of scale in production grow, allowing more investment in promotional activities that grows the market.