I won an item in the container store for 200 Free XP, but when I've had them before, they seem just to add 200 to my Credits.... Not freeXP that would say make you be a able to make an upgrade to another tier tank easy. For example I expected that if I had 25 xp on my tier 8 tank and the next tier up tank is 225xp I could now get it. But it doesn't seem to work that way. What the heck is the Free XP. Btw, they had one a while ago in the store for $1.99 and I thought it would do that but it didn't and they refunded me my purchase.