Just noticed a interesting double dipping opportunity at Sobeys (NB):
I always buy NB Liquor gift card there, since the liquor store is next to the grocery store, thus getting twice the MR points on my Amex Gold.
Sadly, you don't get Air Miles for GC purchases. But I was delighted to notice that my $50 purchase allowed me to get 5 Jamie Oliver stamps because of this promotion currently running: http://betterfoodforall.sobeys.com/jamie-oliver-knives/
I was aware from the T&C that Gift Card purchases were not considered grocery purchases, but it seems the system still allow them (my receipt was explicitly showing the 5 stamps earned, and the GC was my only purchase, so definitely not a human error from the cashier).
Nothing crazy, yet an excellent surprise — this loophole might be convenient to top up my stamp balance next February.