I wasted 20 minutes the other day trying to take advantage of the latest offer, trying several times to purchase, only to be to told "Your cart does not meet the requirements" each time.
If you're going to advertise offers, then make clear you are excluding your non-US customers.
I notice the later adverts were amended to say "US only", which is a start. But as you ship direct and dont have a dealer network, I really dont understand why you choose to penalise non-US customers in this way. I note that all your recent discount offers were valid only for US customers only. Seems odd, and it sends the signal that you dont care much about non-US customers.