The single-business strategy calls for a firm to rely on a single business, product, or service for all its revenue. The most significant advantage of this strategy is that the fine can concentrate all its resources and expertise on that one product or service. However, this strategy also increases the firm’s vulnerability to its competition and to changes in the external environment. For example, for a firm producing only VCRs, a new innovation such as the DVD player makes the firm’s single product obsolete, and it may be unable to develop new products quickly enough to survive.