I've noticed that when I ctrl LMB click it first places a vert but all repeated actions afterwards automatically connect edges to newly created vertices.

Also, it doesn't appear that I can create a free floating face (although not sure why I would) as the last edge will not connect to the first vert in the series to complete the box.

should also mention, from the tut I read, 'W' is necessary, once, afterwards to remove double verts made during the process.