i understand that promo cards are cards that they are testing now, because many of them are horribly powerful (ballista) and others are.....well...with a good picture xd, it´s normal that in this format promo cards aren´t permited in tournaments, because that would be a big mistake, all people spend money for 3 ballistas and storm staff and another powerfull cards and the game would be boring.
I prefer that in the future promo cards would be cards as teleport or some cards that normally are very used and are very few in the box, i need 2 teleport for each mage.