When extending a brand, what quantitative metric is MOST directly impacted?

When extending a brand, market share is the quantitative metric most directly impacted. Brand extension involves using an established brand name to introduce a new product or service in a different category. The immediate effect of a successful brand extension is an increase in the overall market share of the extended brand. This is because the new product line gains immediate recognition and acceptance due to the parent brand's existing equity, potentially capturing a portion of the market previously held by competitors or fulfilling unmet consumer needs. For example, if Dove, known for its soaps, extends into deodorants, the overall market share of 'Dove' branded personal care products is expected to increase. While other metrics like brand awareness, sales volume, and customer acquisition might also be affected, market share directly reflects the degree to which the brand extension has penetrated the new market and captured a portion of the total available sales.