Market share is said to be a key indicator of market competitiveness, i.e. how well a firm is doing against its competitors. "This metric, supplemented by changes in sales revenue, helps managers evaluate both primary and selective demand in their market. That is, it enables them to judge not only total market growth or decline but also trends in customers’ selections among competitors. Generally, sales growth resulting from primary demand (total market growth) is less costly and more profitable than that achieved by capturing share from competitors. Conversely, losses in market share can signal serious long-term problems that require strategic adjustments. Firms with market shares below a certain level may not be viable. Similarly, within a firm’s product line, market share trends for individual products are considered early indicators of future opportunities or problems." Also,"Market share competition drives companies to support climate change policies with a view to imposing costs on domestic competitors"