The prop shop where Britney Spears claims she rented her famous dancin' knives is seeing a big boost in sales after the shout-out ... and it's helped pull the store out of a financial hole.
The manager of Hand Prop Room in L.A. tells TMZ ... online traffic and calls to the shop have doubled since Brit name-dropped their spot Thursday on Instagram. Rental sales for their props, especially knives, have gone up 50%.
We're told everyone in the sales department has been getting calls from people asking about the singer and her knives -- the manager has been fielding tons of calls about Britney.
The manager says Britney is partially to thank for saving the store ... the place has been struggling during the writers' and actors' strikes this year.
The entertainment industry is the shop's bread and butter, but no work meant fewer rentals ... leading to a big financial struggle.
He says the store's been bumping her songs nonstop ever since her post -- so the promotion goes both ways!
As we reported, Britney shared her alarming dance video Monday, swinging and clanking the blades around with a caption that read, "Don’t worry they are NOT real knives !!! Halloween is soon."
She doubled down on the prop knife claim Thursday, claiming her team rented the props from Hand Prop Room -- also confirming her dangerous moves were inspired by Shakira's VMA performance.