They're giving away SC2 for free who has WOW subscription on 11/13 00:00 KST(GMT +9). And the cheapest subscription(7days) is 7040KRW, which is approx. 6.5USD.
(SC2 was 69000KRW on release, which is 63.6USD. this is about 90% sale. It is currently 40000KRW though, still you can say it's over 80% off.)
I don't know about whether foreigners can benefit from this. I'm just saying.
Maybe they're trying to attract people for HotS release?