Traditional free trials aren't always crippled; it used to actually be standard in software that the free versions were useful in their own right, and the rise of "crippleware" that was basically useless on its own was initially fairly controversial in the shareware community.
I mean, Doom could've been seen as a "freemium" FPS, where you get the entire FPS engine and several levels free, and only pay if you want to buy bonus levels.
(Admittedly, that's software v. service, but in the same era, some BBSs ran on a service-based freemium model as well, providing free access to anyone, but letting users pay for certain features like extra download quotas or time quotas.)
I didn't say that. In fact free trials are often fully functional. But trials expire. That makes them different from 'freemium'.
Shareware is a little different. There are at least two kinds - shareware that is limited and its purpose is largely demonstration to entice you to buy the full product. Doom was that kind of shareware, the stuff you paid for was not the 'bonus levels' it was the actual game.
There's also, less commonly, shareware that's useful as is but certain extra features cost money. This is the closest analogue to a 'freemium' web service.
The original question, though, was 'what's the difference between a free trial and freemium'. And the answer remains the same, free trials expire, freemium done right is a useful standalone product in its own right that you can use for as long as you like.
I mean, Doom could've been seen as a "freemium" FPS, where you get the entire FPS engine and several levels free, and only pay if you want to buy bonus levels.
(Admittedly, that's software v. service, but in the same era, some BBSs ran on a service-based freemium model as well, providing free access to anyone, but letting users pay for certain features like extra download quotas or time quotas.)