Wonder why Most Retailers Don't offer PSN Cards?

Playstation Lifstyle like most consumers have waited patiently for PSN cards to hit the general public. For quite some time they were only available on Military Bases (for some reason or another), then retailers like Best Buy finally started caring them. Recently I passed by a 7-11 store and saw on the outside banner that they are selling Xbox Live subscription cards. Why can 7-11 sell Xbox live cards but not PSN cards and why has Gamestop (the 2nd largest game retailer in the nation after Walmart) still have not received them, here is why…