thanks for preserving the link in Matt's post :)

I don't have the references to back it up, but I think your virtuous circle argument (people use the tools because they are supported by them, people use the tools because they become comfortable with them, leading to people using the tools because they are more supported by them) has a lot of merit.

It could be that the need for validation (esteem) is the starting point for some people - my argument was that of Maslow's D (deficiency) needs, the need for esteem was the biggest WIIFM for bloggers. I really liked Matt's diamond model extension that applies to the whole social computing universe - I first saw it hand-drawn on a scrap of paper and it impressed me with its elegant simplicity.

Best regards, Andrew