That's one sweet deal!

After reading through a whole catalogue of different products, I was met with this on the last page (conveniently placed next to the ordering form). The advert promises a ‘free’ gift for customers who have spent over £59.99. What’s more, the catalogue claimed the ‘gift’ had a retail value of £9.99 and so the real message was that the customer could get £69.98 worth of products for just £59.99.

This clever advert employs the ‘that’s-not-all’ technique – consisting of offering a better deal to the customer than the one they originally thought they were going to get. This technique is frequently used in sales and is effective in persuading the customer to spend their money. Burger (1986) examined the effectiveness of this technique in his paper which involved several different experiments.

The first two experiments tested the effectiveness of the technique. The experiments involved a bake sale in which no prices were listed. Cupcakes were placed on the table but the cookies were hidden from view. When a person asked about the price of the cupcakes, they were told that the price was 75¢ and then (after a pause) that they would also get two cookies. In the control condition, people were just told that the cupcakes and two cookies were 75¢. It was found that more participants purchased cupcakes in the ‘that’s-not-all’ condition (73%) than in the control condition (40%); using the technique increased sales by 33% (see fig. 1).

	‘That’s-not-all’	Control
Sales (percentage)	73	40

Fig. 1: The table shows that using the technique resulted in a higher percentage of participants purchasing cupcakes from the stall than when the technique was not used. In terms of the advert depicted above, this suggests that customers are likely to spend more money on products from the rest of the catalogue in order to obtain the 'free' gift

So the first two experiments showed that the technique is effective in increasing how much customers buy. Experiments 3, 4, 5 and 6 examined two possible mediators of the effect – why the technique works.  One possibility is the notion of the norm of reciprocity: ‘If I do something for you, you should do something for me’. In terms of the ‘that’s-not-all’ technique, the seller has made the deal better for the customer and so the customer should do something nice for the seller – buy the product. A second possibility involves the use of the anchoring heuristic: The customer’s anchoring point for buying the cupcake is the initial price. The anchor price of 75¢ is first introduced; the customer deliberates this but then the addition of two cookies makes the offer seem even more reasonable than if one cupcake and two cookies for 75¢ was the first deal offered.

The ‘that’s-not-all’ technique works because the sweetening of the deal creates a feeling of indebtedness which increases compliance. So in the advert described above, the customer feels as if the seller is doing them a favour by giving them the cookie cutters for free – this makes them more likely to spend over £59.99 on products from the rest of the catalogue.

So what’s the lesson here? If you want someone to buy something, tell them they get something for free. If you want to avoid being duped by this technique, ignore the free gift – you can buy cookies cutters for £1.00 in Poundland instead (the £9.99 retail price mentioned in the advert is exorbitant).

Burger, J. M. (1986). Increasing compliance by improving the deal: The that's-not-all technique. Journal of Personality and Social Psychology, 51, 277.