When did Valentine's Day become commercial?

Valentine's Day has been associated with romantic love and gift-giving since the Middle Ages, but it did not become a major commercial holiday in the United States and other countries until the latter half of the 20th century. The increased commercialization of Valentine's Day was likely driven by a combination of factors, including the growth of consumer culture, the rise of mass media, and the influence of advertising. It's difficult to pinpoint exactly when it became commercial, but by the mid-1900s, Valentine's Day had become a significant holiday for the retail and greeting card industries.