Think of a firm that has attained a differentiation focus or cost focus strategy. Are its advantages sustainable? Why? Why not? (Hint: Consider its position vis-à-vis Porter's five forces.)

Yes they are sustainable

Explanation:

The strategies mentioned in the question were laid out my Michael Porter and therefore, we can look analyse his model to understand whether these strategies are sustainable or not.

Porter has categorized strategies into 3 broad categories: Cost Leadership, Differentiation, and Focus strategies (all three are known as "Generic Strategies). Focus strategy is branched out into two sub-segments known as Cost Focus and Differentiation Focus.

Now, the question has already clarified that the strategies in question are both focus strategies. So lets understand what each entails.

Differentiation Focus: A strategy in which the company aims to gain market leadership in a focused market (a specific market) through strategic differentiaion. This strategic differentiaion involves offering a specialized service or a unique product in a niche market. Cost focus strategy is similar in the sense is that that the aim is to offer highly low cost products/services to a niche market. Because of the focus on these niche markets, company's develop a strong understansing of the consumer thereby developing strong brand loyalty with that particular customer base. The key ingredient, again, is that the competitive advantage is being harnessed by focusing just on a particular niche market. Another key component is that the companies using this strategy rely on the consumers in the target market having different needs, tastes, and requirements than consumers in other segments in the industry.

Now, these strategies by desig were put forth my Porter has being sustainable. Hence the term "generic strategies" in that they can be broadly used to create and sustain performance. The focus strategies as defined above are sustainable since they harness the power of having priority knowledge of their target market to provide appropriate services and products. The high brand loyalty and knowledge of consumers give them an edge over competitors (competitive rivalry). Supplier power depends on the nature of products being offered therefore it cant be taken into consideration. Buyer power can be managed since you are prodiving unique service offerings to unique customers. Threat of substitution depends on the product and service offering. Threat of new entry by larger player exists, but due to the focus that the company had in the target market, barriers to entry (long strong brand loyalty) can be developed.