Sheila, this is a neat listing of ways to use Biznik, and I can personally vouch for the value of most of them!
You asked Bill about his recent article, which leads me to add another item to your summary: On our profiles, articles are listed in descending chronological order, so if we go to Bill's we can easily spot what he has been writing lately.
Thinking about the Biznik profile pages leads me to note another cool updated feature for paid members, the listing of fellow Pros who have visited in the previous week, as well as how many "unidentified others" have dropped by.
I usually write a note to the named members to thank them for visiting, which helps to build connections. Even the raw number of unnamed visitors is helpful: If it's very low, I realize that I've been neglecting the community, so I get involved again with a post, some comments or an article.