Marks & Spencer shoppers believe they've worked out how to be one of the 1,000 people that gets their food shop free every week.
One mum of three shared how she won the weekly freebie on her @mrsbee_x_x TikTok account adding the comment: "When this happens and you've only bought bread, milk and salad".
The TikTok user shared an image of the M&S self-service checkout screen which said: "Congratulations! We are treating you to your shopping for free today to say thanks for shopping with Sparks.”
The supermarket says the "lucky transaction is chosen at random in every store and online every week” and you are told you have won the free shop when you reach the checkout and scan your Sparks card.
This means there is no way to know if you should chuck a few treats into your shop. But some Tiktok users think otherwise.
TikTok user @leoca557 said@ "It's probably price specific though e.g only orders under £10."
Another user, @melonaimeemelon added: "This happened to me! I did a whole food shop and forgot wraps so went back to get wraps and of course, I got free wraps!"
Another shared how it happened to them when they were only buying some frozen broccoli whilst another said their wife had also won the freebie but for a shop which consisted of only one pint of milk.
Other users shared how they believed this was just an "urban myth" and nobody actually won a free shop with it.
However, some users disproved the "only offered to shops under £10 theory" by sharing how they had won with M&S shops up to £50.
Jaina__solo said: "Happened to me in September! For about £50 of shopping!"
Another user, @kemm82 added: "My brother has had this twice! shopping worth over £30 both times."
User @samzolly said: "Whilst visiting London last year near my birthday I was treated to the Mother's Day roast dinner - my basket totalled £40! Thanks, M&S!"
Of course, these comments are just based on customer speculation and the official line from M&S is that the winners are chosen at random.
We've approached M&S for comment and we'll update this article when we get a response.
The supermarket introduced the freebie competition in 2020 after it relaunched its Sparks Card loyalty scheme.
Before this, M&S used to allow shoppers to collect points through its Sparks scheme, which could then be converted into vouchers to spend in stores.