suppliers usually have two kinds of problems when dealing with mcdonald's. 1. they can't produce enough to supply all of the mcdonald's franchises in the country or at all times of the year. 2. when mcdonald's puts pressure on them to lower prices, thus hurting the supplier's bottom line. so either the $5 deal is causing them to sell so many fries that their supplier is having trouble keeping up, or in order to keep that deal at $5 mcdonald's is firm on price.
United States