Some time ago, I started a thread about Freemium models as a way to entice visitors to sign up. Now, I saw this very interesting post on Mashable about the various business models online businesses use to grow their community. So what do you think?
http://mashable.com/2009/07/14/social-media-business-models/

I am working with an early stage startup and I recommend the freemium model though it may not be the best model for others.

Paid content model is also growing fast. Users now expect to pay for good subscription based services. This is not as much of a problem as it used to be before when user expectation was to receive content free.

The 5 in the link in the original post are all viable and as you allude to, the type of business will dictate which model is the best. As for Paid Content, I would want to see some statistics and results before I would recommend it to a client.