I don't know of any others going on right now. Just have to catch the promotions while they are going on. They will usually get posted in here once a company is offering one. Free tax stamp promotions don't come along often because the manufacturer isn't discounting the product they manufacture, they are actually having to write a check out of their pockets for the $200.
Q did a promotion awhile back that I liked, they let you purchase only the stamp and start the form 4, then you could pay for the can over time, I forget how long they gave you but it was a few months at least to pay off the can. So it was essentially lay away, but you got to start the form 4 immediately.