I had this one flight back in July that had a general boarding. As I was approaching the gate, I heard the GA giving the usual speech that they are about to start boarding by rows. She then anounced boarding all rows. I decided to watch a bit. No one moved, they stayed seated. She then re-announced "now boarding all rows" I seemed to go smoothly once people caught on. Now that I think about it, it was a 733 to MSP so many passengers may be use to it from NW.