How we change what others think, feel, believe and do
Offer them something that appears to be very good value. This should be a real bargain, an offer they can't possibly refuse, even if they were not thinking about it.
Later, replace the item with something of less value to them (and more profit to you).
A car sales showroom puts a basic car outside with a very low price-tag. Once the customer is interested, the sales person trades them up to a more expensive model.
Would you like to go out to this really expensive restaurant? ... Oh dear, it's booked up. Never mind, we can go to the usual place.
When the person sees the initial item of high value they cognitively close on the idea of acquiring it and hence The early bait thus moves them from a negative position to one of commitment.
When the high value item is removed, then they enter a state of anxiety in which they seek to re-enter the comfortable closed state. They thus seek to satisfice, accepting almost any solution that will get them back to that comfortable state.
There may also be an element of commitment to the person making the offer. If I offer something to you, you feel some obligation to me. If I then switch the offer, especially if the switching seems reasonable, then you are likely to accept the second offer out of a sense of obligation to me. To do otherwise would expose myself as inconsistent and break bonding between us.
Although common in sales, this method was first researched by Joule, Gouilloux, and Weber (1989), who called it the lure procedure. They invited students to watch interesting film clips (and hence got a lot of volunteers), but then switched the task to memorizing lists of numbers. In the control group that was just asked to help by memorizing numbers (no initial film-clip offer), only 15% agreed, as opposed to 47% who had been first offered the film-clip experiment.
Bait-and-switch is similar to Low-ball. Low-ball is used in a single transaction, for example in the direct conversation between a customer and a sales person. In bait-and-switch, the bait (such as in an advert) is often separate from the direct sales activity during which the switch is made, for example by saying the advertised product is not available (but a higher-priced, similar product is). Also, low-balling is often based more in money, while bait-and-switch typically is about different products.
The bait and switch technique is a 'sequential request'.
Cialdini, R. B., & Trost, M. R., (1998) Social influence: Social norms, conformity, and compliance. In D. T. Gilbert and S. T. Fiske (Eds.), The handbook of social psychology: Vol. 2. (4th ed., pp. 151-192). Boston: Mcgraw-Hill.
Joule, R. V., Gouilloux, F., and Weber, F. (1989). The lure: A new compliance procedure. Journal of Social Psychology, 129, 741-749.