The phenomenon was first noticed on Twitter.
“Those people buying whips at Decathlon even though there's no horse parked in the car park, we can see you,” commented a Twitter wag.
And Decathlon responded with some interesting observations.
“A few months ago we noticed an increase in the sales of whips. We analyzed our numbers to try to see what might have sparked the increase. Then we realised it coincided exactly with the release of 50 Shades Darker.”
The tweet quickly went viral and even sparked another French stores to join in the banter
Hardware store Leroy Merlin tweeted that “surprisingly” it didn't notice a rise in the sales of hammers on the release of the film Thor.
France's National Film Board (CNC) caused a stir when it rated the erotic Fifty Shades of Grey film as a PG 12 film, judging the movie a “romance”.
So while 12-year-olds could see the movie in France, in the UK it was only available to over 18s.
But not everyone in France was happy with the move.
A Catholic group which succeeded in having Lars von Trier's ultra-violent film “Antichrist” banned from French cinemas, took a case against the erotic romance “Fifty Shades Freed”.