商業模式
Freemium
platform business
Amazon、fiverr
4. aggregator
Uber、Airbnb
7. EdTech
Freemium subscription
Coursera
Free trial subscription
Skillshare
Marketplace
Udemy
Ad revenue
Duolingo
8. Lock-in
Apple、SAP
9. API license
Twilio、Sendgrid、Google Map APIs
Android、Firefox、MongoDB