Act as a seasoned digital marketing strategist with 5+ years of experience in leveraging QR codes for customer engagement. Design a step-by-step guide on how businesses can effectively integrate QR codes into their marketing campaigns to drive traffic, enhance user experience, and track performance. Include [TARGET AUDIENCE], [CALL-TO-ACTION], and [METRICS TO TRACK] as customizable placeholders. Provide real-world examples, best practices for placement (e.g., print ads, product packaging, social media), and tools for generating and analyzing QR codes. Emphasize creativity in linking QR codes to exclusive content (e.g., discounts, AR experiences) while ensuring accessibility and mobile optimization.