Final answer:
The main concerns with brand extension strategies are cannibalization and meeting quality expectations, which, if not managed correctly, can adversely impact the overall brand and its market share.
Step-by-step explanation:
The two main concerns associated with a brand extension strategy are cannibalization and meeting quality expectations. Cannibalization occurs when a new product takes sales away from the same company's existing products, rather than generating additional total sales or taking sales away from competitors. Meeting quality expectations is paramount, as a failure to do so can harm the parent brand's reputation, especially if the new product's quality is perceived as inferior.
Notably, reduced brand recognition is not typically a concern with brand extensions, as the main idea is to leverage the existing brand's equity. Developing unique advertising campaigns and dealing with duplicate products from competitors are also concerns, but not as directly related to brand extension strategy as cannibalization and quality maintenance.