According to one legend, Valentine actually sent the first 'valentine' greeting himself. While in prison, it is believed that Valentine fell in love with a young girl — who may have been his jailor's daughter — who visited him during his confinement. Before his death, it is alleged that he wrote her a letter, which he signed 'From your Valentine,' an expression that is still in use today. Although the truth behind the Valentine legends is murky, the stories certainly emphasize his appeal as a sympathetic, heroic, and, most importantly, romantic figure. It's no surprise that by the Middle Ages, Valentine was one of the most popular saints in England and France.

In the second half of the twentieth century, the practice of exchanging cards was extended to all manner of gifts in the United States, usually from a man to a woman.Such gifts typically include roses and chocolates packed in a red satin, heart-shaped box. In the 1980s, the diamond industry began to promote Valentine's Day as an occasion for giving jewelry. The day has come to be associated with a generic platonic greeting of "Happy Valentine's Day." As a joke, Valentine's Day is also referred to as "Singles Awareness Day." In some North American elementary schools, children decorate classrooms, exchange cards, and eat sweets. The greeting cards of these students often mention what they appreciate about each other.

The rise of Internet popularity at the turn of the millennium is creating new traditions. Millions of people use, every year, digital means of creating and sending Valentine's Day greeting messages such as e-cards, love coupons or printable greeting cards. wikipedia