As nobody responded I assume this was a dumb question and Type Bid does mean the trade was initiated by the buyer. In that case I am forced to conclude that there has not been even one transaction initiated by a seller of bitUSD in at least the last week.

In the bitUSD market interface in the client, the Blockchain Orders History shows all transactions (that I can see) as Type Bid. Does this mean the trade was initiated by the bitUSD buyer? Is there also a Type "Offer" and why can't I see any of these in the list (it goes back many days, all showing Bid)?