-Web Stores (like App Store, Google Play, Chrome Web Store, Microsoft Store, etc.)
-Episodic Entertainment and expansion packs
-Ads & Sponsorship
-Purchase high class upgrades with real money
-Register & Log in to Play (eg. Premium Membership)
-Downloadable Content
-Kickstart Project
-User-Generated Content
-Partnership
-Pay for Storage Space
-Host Private Game Server
-Licensing
-Subscription
-Micro-Transactions (eg. facebook)
-Donationware
-Pay for Time (like arcade machines)
-Player-to-Player Trading/Auctions
-Foreign Distribution Deals