Final answer:
During the growth stage of the product life cycle, sales increase rapidly as consumer awareness grows, and competition increases as other companies enter the market.
Step-by-step explanation:
Two key characteristics of the growth stage of the product life cycle are a rapid increase in sales and increasing competition. During this stage, more consumers become aware of the product, leading to a surge in sales. Additionally, the success of the product attracts other companies, intensifying competition. Marketers may work on stimulating primary demand for the product category rather than just their own brand.