As new firms enter the competition, the demand for the single firm is reduced. This means that the demand curve will shift to become less steep. This is indefinitely due to more firms introducing the product. When a single business was involved in catering to clients the demand for the product was higher.
However, when more businesses came into view, the demand grew lower and lower as more firms catered the product. This is how competition works. The more the sellers, the lower is the demand for a single firm. This also plays a major part in the investment world when entrepreneurs are considering a new startup.