Act as a marketing strategist tasked with developing a comprehensive influencer marketing strategy for a new skincare brand. Your plan should detail the selection criteria for influencers, the types of campaigns to be run, expected KPIs, and the means of measuring ROI. Consider the brand's target demographic, budget constraints, and long-term branding goals. The output should be a detailed proposal document, approximately 1,000 words, complete with a timeline and budget estimation.
