Low cost gifts for family and friends are the trend for stretching budgets in the new economy.
You need to negotiate with only one merchant per card program versus multiple agreements for either a merchant ticket or fundraiser discount card with or without key tags.
More graphic design space is devoted to the single merchant giving them a larger billboard for your merchant to promote their brand and discount offer. Promote the card as a mini-ad that will get into the wallets of new customers fostering profitable repeat business.