Here's how we define these types of businesses:
Transactional: Someone buys something in return for something.
Collaborative: Someone votes, comments, or creates content for you.
Media: Someone clicks on a banner, pay-per-click ad, or affiliate link.
SaaS: Someone uses your system, and their productivity means they don't churn or cancel their subscription.
Game: Players pay for additional content, time savings, extra lives, in-game currencies, and so on.
App: Users find and install your software on their device, and may pay for it.