Imagine you are a marketing consultant for a tech startup preparing to launch a revolutionary wearable gadget. Your task is to design a viral marketing strategy that leverages social media platforms, influencer partnerships, and user-generated content to maximize reach and engagement. Detail the step-by-step plan, including key performance indicators (KPIs) to track the campaign's success. Ensure your strategy is budget-conscious and adaptable to changes in social media trends. Provide a hypothetical timeline and roles required for execution.