Laziness: an enabler of common sense?

A friend sent me a link to an interesting post about the risk of collapse of the Web 2.0. The article argues that users out there will become tired of playing around with platforms like Friendster, MySpace or Facebook as the "natural" human attribute of laziness becomes dominant as a driver of online beavior and that this will actually lead to a burst of the Web 2.0 bubble.
The point is valid in the sense that as the power of "new" fades, the motivation of individual users to spend time doing work for free will drop. However, there are still quite a few things happening out there which may be done without the people doing them getting paid and which bring at least indirect benefits to those people, such as for example public image or the opportunity to show how good they are at specific tasks or in given industries. In other words, in the vast mass of participants to phenomena like Facebook, there is a fraction of people who actually derive business value out of their participation to the platforms that are so characteristic of what has been called Web 2.0, like for example Wikipedia or targeted blogs like Culture Buzz.
The question then becomes: how does one actually measure the indirect benefits they get from participating to communities like LinkedIn or Facebook? By which means one can assess the relevance and value of platforms allowing users to host online applications is another question, that I think is particularly relevant in view of a comment made by my friend David on a recent post about Facebook.
I will also add that although I have no illusions as to the dark sides of the human psyche, I don't believe laziness to be inevitable or undesirable. Usually we humans face problems when we abandon ourselves to the extremes like complete passivity as resulting from extreme laziness or frantic activity as caused by workaholism... Bottom line: in order to identify value drivers for the web 2.0 space better skills in psychology may be needed.