I have all mine on board cept for double ones, but they are removeable.
As far as the trading goes, I guess it would just be up to the people involved as to when they wanna do it. Cause if someone makes one trade, they may have missed out on one that would have benefitted them more later on.
They been playing commercials for it on tv for the last week or so. If they had this going during the summer, I would have won something. I ate there almost every day and lost 10 pounds!