In developing African countries, a considerable body of knowledge exists about the evolving stages of corporate social responsibility (CSR) practices from mere philanthropic actions to damage control strategy, especially in the mining sector. However, little is known about the emerging strategic CSR as a competitive strategy particularly its dimensional outcomes among diverse sectors in the region. Applying a multidimensional perspective of corporate social responsibility activities, we explored how customers’ perception of a firm’s economic, legal, ethical, and social responsibility actions influence the firm’s product rating, consumer loyalty, and firms’ strategic legitimacy among telecoms subscribers in Nigeria. A probability sampling technique was used to select 126 subscribers with a proportionate representation of the five mobile phone service providers in Nigeria. From the collected data, descriptive statistics were applied to analyze the demographic profile of the participants while the partial least squares structural equation modeling (PLS-SEM) was used to test the hypotheses. Contrary to expectations, the outcomes suggest that consumer perception of telecoms firms’ economic responsibilities has no significant positive influence on the firms’ product rating, consumer loyalty, and the firms’ strategic legitimacy. Conversely, the outcomes support our propositions that the consumer perception of telecoms firms’ social, legal, and ethical responsibility actions has a significant positive influence on the firms’ product rating, consumer loyalty, and firms’ strategic legitimacy. The findings suggest the need for telecoms firms to focus on social, legal, and ethical responsibility dimensions as competitive strategies.