On the 4 day cruise we used points for, we received a beach towel in each cabin. On the 7 day cruise (didn't use points for this) we went to a member gathering and received luggage tags, baseball caps and a couple more beach towels. They had a contest and gave away stuff like tote bags and t-shirts. They don't do member gatherings on the 4 day (at least they didn't then).
Have fun.
HBC