Refer a Friend Referral Cards by J32 Design. Encourage your customers to refer a friend with these beautiful floral referral cards. This customizable template can be personalized with your coupon and business information. Flower themed refer a friend cards come in the standard business card size of 3.5 x 2 inches. Ideal for small businesses who would like to start a referral program for their customers to gain new clients. Floral Flower Referral Cards created by J32 Design.