Valentine's Day is one of the most popular days of the year for online retailers as consumers search for heartfelt gifts for Her and Him.

During the first two weeks of February, a total of 90 million Americans visited sites in the top four Valentine's Day-related shopping categories, a number that is down by 13 million visitors, or 12.7%, over last year. The sharp drop in traffic was most dramatic for traditional gift sites: greeting cards (-23%) and jewelry (-19%). Restaurant reservations and flower delivery sites had smaller year-over-year changes: -12% and -9%, respectively.