Originally Posted by
FriendlySkies
+1
The duty free shops I've seen at SFO and JFK, they have a sign stating that you must have an international boarding pass to be able to visit/purchase anything from the store..
I visited an SFO duty free shop after arriving domestically last week. No one asked me for a boarding pass. I doubt the employees care enough to check as far as visiting as you'd get denied at point of sale in the end.
OTOH, LAX allows domestic pax to buy at dutied prices. Handy for a last minute gift to a host picking you up from the airport.