But in your example, the absence of photo albums on myspace is punished quite heavily in practice.

Right up until they were sitting on a billion dollar valuation, you could not even make your photos private to just your friends. Sharing was mandatory.

Note that I am not saying that zero content should be available until the user has made a contribution to the site, just that the site should at least keep something special for people who do. Most importantly, I am not saying that this practice is best for all sites or even the majority.