Test "get one free" against the equivalent discount

When to use it

When a promotion is framed as a percentage off on a product people buy more than one of.

How to run it

1. 1Run buy-one-get-one against the equivalent percentage off, on the same product and the same traffic.
2. 2Test "second one half price" where a full BOGO would cut margin too far.

Why it works

Raise the perceived value of acting

People are poor at percentage math and prefer getting more over paying less. In Rao and Chen's bonus-pack research, shoppers rated an offer of extra free product as better value than a mathematically equivalent price cut.

Source: Rao & Chen bonus-pack research