QR Code AI: AI-designed QR codes, $14,900 MRR on SEO alone at a 95% margin
QR Code AI sells AI-designed, trackable QR codes as a bootstrapped SaaS grown on SEO only, with $14,900 in verified monthly recurring revenue and a founder-stated 95% margin — the highest in its cohort, because it spends nothing on traffic. It is the smallest, cheapest pattern in this set: one feature, search distribution, near-zero cost — with a narrow niche that is easy to copy.