The idea of Christmas seals began in 1903 with Einar Holboell, a postal clerk from Copenhagen.  By 1904, with the King of Denmark taking an interest, the first seals were printed and sold, raising funds that were used to:

Although the seals cost only a penny, they were immediately successful, funding the building of two hospitals for children with TB.  By 1907 the idea had spread to Sweden, Norway and the United States.  Many thousands have since been saved from lung disease because of the money raised by Christmas seals.  The first Christmas seal in Canada, which illustrates this question, was issued in 1927.  Click the illustration to visit the Christmas Seal Story page of the Canadian Lung Association.