Krispy Kreme customers can send Valentine e-cards by scanning a QR code on boxes of the brand's special heart-shaped doughnuts. The holiday is also the occasion for Krispy Kreme to leverage Facebook, where users are invited to customize a Share Your Heart Facebook cover photo. "If the QR codes are incorporated into a campaign over at least two weeks, you will have measurable results. ... You receive more scans when the QR codes are integrated into multiple printed pieces and placed where consumers can see them in your shop and at their eye-level," said Kelley O'Brien, a spokeswoman for Krispy Kreme.