Loss leader

Three cans for a pound in Poundland. Coke is 97p in McColls.

I'm fairly confident that Poundland make a profit because people don't know how much things really cost. Yes the cans are cheap, but their washing up liquid is £1 a bottle. The same bottle is 46p in Asda.

So which is the better deal?

To get something you don't need or want at half price, or to get something you really want and need for a price that is twice its value?