FWIW IMO: This should be marketed to the twitter croud, not the facebook crowd. I have no interest in writing journals for my friends and family, and even if I did, there won't be many who want to read what I write (in my personal network).

But I can see writing for folks with the same interests in tech, business, books or what not. So I am willing to open up my personal journals, but only to complete strangers (anonymously).