The rapid expansion of frequent-flyer programs is due to the fact that loyalty marketing relies on the earned loyalty of current customers to attract new loyalty from future customers. Incentive programs that are exclusive must strike a balance between increasing benefits for new customers over any existing loyalty plan they are currently in and keeping existing customers from moving to new plans. Hallmark did this through devising a program that directly rewarded customers not only for buying merchandise and utilizing Hallmark.com, but gaining additional benefits through referring their friends.