In Great Britain, Valentine's Day began to be popularly celebrated around the seventeenth century. By the middle of the eighteenth century, it was common for friends and lovers in all social classes to exchange small tokens of affection or handwritten notes. By the end of the century, printed cards began to replace written letters due to improvements in printing technology. Ready-made cards were an easy way for people to express their emotions in a time when direct expression of one's feelings was discouraged. Cheaper postage rates also contributed to an increase in the popularity of sending Valentine's Day greetings. Americans probably began exchanging hand-made valentines in the early 1700s. In the 1840s, Esther A. Howland began to sell the first mass-produced valentines in America.