This is universally known as marketing technique. This is one of the biggest marketing ideas in recent years. This can come in a variety of offers from buy one get one free to buy one get one 50% off. But no matter the variety, they all do one thing very well - the drive sales. In fact, the reality is if you do a BOGO 50% off, it is the same as 25% of your entire purchase for the customer, but it feels like so much more.