A young woman discovers she's listening to "The Worst Song in the World" on her headphones in a funny new ad from French retailer Monoprix--but you'll have to get to the end to find out why she can't stop.

In reality, it's no hardship, because the song itself, together with the video, is hilarious. It's a mix of cheesy '80s rock with horrible chord changes, a bad sax solo, random Spanish words, an obligatory rap section and some fantastic lyrics ("Maybe your cat just butt-typed on your laptop" is an explanation for how it got on to the girl's playlist).

Finally, we discover the source of her troubles--the grimacing girl can't actually stop to change the track because she's carrying heavy grocery bags. If she had her groceries delivered, as Monoprix now offers, she wouldn't be in this predicament. It's something of a creative leap, but the journey there is pure fun.

The ad is by agency Rosapark and was shot by the directing collective Traktor via Stink. It promotes new services by the retailer that include delivery of groceries on foot in less than an hour, and, if you live within 500 meters of the store, the option to leave your cart at the checkout and pay upon delivery.

The campaign will go live on Twitter on April 12 with the hashtag #LaPireChansonDuMonde (The Worst Song in the World). It also features a social media element in which tweeters can have their messages retranscribed with the song's instrumentals by submitting them to KaraoTweet. Several users will even have their tweets sung by Monoprix's community manager.

Gilles Fichteberg, co-founder of Rosapark, says of the creative process: "To create 'The Worst song in the World,' we had to find the musical universe that would be the farthest away from the young woman's. It was a clash of generations, styles, tastes. But we also strove to create a song that could be a guilty pleasure, the sort of song we love listening to, even if we don't want to admit it."

You said it, Gilles.