Does anyone know if amazon gift cards charged to Discover and Chase Freedom (amazon is a 5% cash back partner this quarter) will earn the 5% cash back or is it purchases of goods only?

I purchase a lot through Amazon through the year and want to just purchase 2-$1,500 gift cards and apply them to my amazon account, since I know I will burn through $3k in purchases by March, 2014 on Amazon. I just want to make sure that I will get the 5% cash back before doing this and that I can also apply the cards to the same amazon account I purchased them from.