This paper examines how demand conditions across alternative markets impact diversification decisions and firm performance by influencing the opportunity costs of deploying non‐scale free capabilities. Using data within the cardiovascular medical device industry, this study shows that: (1) firms with a larger stock of pre‐entry innovation experience are more likely to diversify; (2) firms in a current market with greater relative demand maturity are more likely to diversify; (3) diversification is associated with a performance decrease in the current market; and (4) diversification is associated with a performance increase at the corporate level. These findings shed new light on the self‐selection process of corporate scope, the conceptualization of firm capabilities, and the connection between industry dynamics and resource deployment. Copyright © 2013 John Wiley & Sons, Ltd.