We could sell "........... out!" plastic flags every six months, for them to fill in a name in the blank space.
No! You're cutting off your new sales; making it a one time only product. And assuming the majority can read & write.....
It would have to be a 'rolling product' that is reinvented every six months, sometimes sooner, sometimes longer. Maybe spread into other markets such as flags with 'we steal songs' written on them
