Question for International Followers – Gift Cards

With the upcoming Gift Card Giveaway Hop approaching I’ve been asked if gift cards can be used by someone living Internationally.  I can’t seem to get an accurate answer.

Some people say yes, others no.  I’ve read where they can be used for ebooks but you have to jump through some hoops to make it work.  Also does ship Internationally so it seems like it is possible that the gift cards could be used by someone not in the US but I don’t know.  So here is my question for anyone who might know.

If a blog is offering an gift card and sending it via email can someone in a country other than the US use the gift card?

If you live Internationally have you had an luck using an gift card?

I’m asking because I put US or Int on the linky for the hop letting people know where the giveaway is open to.  I’m not sure what to put after those who are giving away an gift card.