Actually, it's a cheap marketing trick. At least we now know the level of respect the big supermarkets have for their customers...
The Multi-buy non-deal
This is the advertising on the shelves that announces Two for £2, but fails to highlight that there is no saving there - the item's price is £1 each.
But does it make us buy more?
Psychologist Gorkan Ahmetoglu, who wrote a report for the Office of Fair Trading on the influence promotions and offers of savings have on shopping habits, says this type of advertising acts as a subconscious trigger.
"They are triggering the same reaction as when you eat chocolate. The offer will still attract your attention and a lot of people will not look at the single unit price."
I can't find out how old the Stanes sign is, but the name comes from Sir Robert Stanes (13 May 1841 – 6 September 1936), who launched himself on a successful career as a coffee planter in Coimbatore, immediately after he arrived there, aged 17 (http://en.wikipedia.org/wiki/Robert_Stanes)