iTunes specifically is excluded because Apple required it, but it is no different from any of the other 'gift cards' for accounting purposes. Target's own cards and the visa/mc/amex cards are different because of how they are handled in accounting/banking and how the income is taken (earned). When Target sells a Target gift card, Target still owes that person $25 or $50 worth of merchandize so it must carry that amount as a debt. When it sells a Disney card or a Chili's card, Target has no further obligation - Target gets to recognize its $1.22 or whatever it is right then and doesn't care if the person who bought it never goes to Chili's or Disney and the card is wasted. For this reason, Target classifies its own cards as a gift card (a debt) and other cards as entertainment cards (sold, a profit to Target). The visa/mc/amex are bank cards, and there are bank rules to govern them.
Many states do have laws about gift cards, and all these cards are covered the same no matter what name they were sold under. In most states now the cards can't expire without notice, do have a cash value (and in some places the merchant needs to give you cash back if the amount remaining is less then $1), etc.
But just because Target calls it an entertainment card doesn't mean the law doesn't call it a gift card.
Nancy