Buy one, get one free

"Buy one, get one free" or "two for the price of one" is a common form of sales promotion.

The economist Alex Tabarrok has argued, that the success of this promotion lies in the fact that consumers value the first unit significantly more than the second one.

[1] The concept of "buy one, get one free" was devised in the 18th century by retail entrepreneur Josiah Wedgwood.

[2][3] This technique is commonly known in the marketing industry by the acronym BOGOF, or simply BOGO.

Because many foods under such offers have short shelf lives, customers are more likely to pass the products' use by date.