Keys to the castle! Send our congratulations postcards for HomeSmart real estate agents when the deal is sealed. Congratulations postcards are a professional, final touch, and your clients will be impressed you thought of them after the sale. Our low prices on heavy-weight, full-color Realtor postcards cut your costs, without cutting corners on quality. Easy to make in our real estate marketing design center, Bestprintbuy.com real estate postcards are available in two sizes: standard size (4.5" x 5.5") and jumbo (5.5" x 8.5").