Freemium
Freemium combines 'free' and 'premium': basic services are free, advanced features are paid. Most QR code generators offer free static code creation but charge for dynamic codes, analytics, and bulk generation.
Typically 2-5% of free users convert to paid plans. Free users generate word-of-mouth and network effects, reducing paid user acquisition costs. Spotify, Dropbox, and Slack use the same model successfully.