A charitable organization wants to issue discount cards
Question

                Is it permissible to implement the following investment idea?  

The idea is for a charitable organization to issue special cards which will enable the bearer to get special discounts of 15% or 20% or more from various stores, based on an agreement between the charity and the owners of these stores. The charity will charge special fees to be paid by those who will benefit from these cards, which is to offset the costs incurred by the club for employing people to contact the stores and draw up the agreements with the business owners, in addition to buying the machinery for producing the cards and the price of the cards themselves, renting office space, paying employees to receive those who come to buy these cards, paying for advertising, and other expenses, etc.
Praise be to Allah.Producing these cards is not permissible, based on what 
          you have said. That is because the fee paid by those who will benefit 
          from them will cause great harm to those who have no great need to buy 
          those things from those stores. He may think that what he needs is too 
          little, and it will be too much trouble for him to go to those particular 
          stores. A year will go by without him having benefited from this card, 
          or having covered the annual fee that he paid. This is like the way 
          in which insurance companies operate. It will also have an adverse effect 
          on the other stores which do not have an agreement with you. People, 
          or most of them, will turn away from them and will go and buy from the 
          stores with which you have an agreement to refer the people who buy 
          the cards to them. It is haraam to cause harm to a fellow-Muslim. Hence 
          we say that it is not allowed to deal in the cards which some companies 
          make and which are a form of deception on the part of these particular 
          stores, which give this discount to those who have these cards, but 
          the discount they give is no more than the amount by which they raised 
          their price over the price charged in other stores. So they make the 
          person who has this card think that he has gotten a discount, when this 
          is not really the case. And Allaah knows best.