The Lidl Valentine Kiss Detector app came out to reward affectionate people on Valentine's Day. The app was put out by Lidl, a global discount supermarket chain and essentially, it traded kissing selfies for $50 voucher coupons at its stores.

The playful campaign was developed by MRM WorldWide and it's a win-win way to promote fun, romance, Lidl and customer savings. As the Valentine Kiss Detector notes, the act of kissing releases endorphins, so it naturally makes people happy — plus, who doesn't love getting free stuff?

Although Valentine's Day this year has long since passed, an online version of the Kiss Detector is still available and you can try puckering up with a parter via webcam at lidlkiss.com.