Gumroad sits third in V3.2's platform registration queue, targeting 6M+ users in the creator marketplace. Unlike ResearchGate (academic) and Medium (content), Gumroad serves as a pure commerce channel for V3.2's three digital product packages: Disproved Conjectures, Quiet Rooms Art Collection, and Mathematical Visualization Guide. The admin confirmed Gumroad registration works without credit card, though receiving payments may require one.