I wouldn't call 'Free trial' the 'original freemium model' Surely, its the original 'try-before-you-buy' model.

So we're left with only two options:

1) Active free users - adding value by doing something, like creating content

2) Passive free users - adding value by just using the service, like attracting others on a dating site

Users that neither do something useful nor attracting others should be forced out (?) or forced into the paying group (maybe by offering a fix length period).

This will be another way to look at 'try-before-you-forced-out' model, where one can prove her usefulness to the service