Interesting example from Intel’s Timothy Mattson regarding the dizzying array of languages currently in vogue for parallel programming:
They created two displays of gourmet jams. One display had 24 jars. The other had 6. Each display invited people to try the jams and offered them a discount coupon to buy the jam. They alternated these displays in a grocery store and tracked how many people passed the displays, how many people stopped and sampled the jams, and how many subsequently used the offered coupon to buy the jam.
The results were surprising.
24 jar display: 60% of the people passing the display sampled the jam, 3% purchased jam.
6 jar display: 40% of the people passing the display sampled the jam, 30% purchased jam.
This is a common merchandising technique. Just put less of the item you want to sell on the rack. In fact ... you can even arrange items slighly off center and put fewer brochures next to it. The appearance that everyone else is buying one will get you more buyers. This bucks the common conception of supply and demand. I used to use this and another technique to sell macs when I did market representation for Apple back in 1998-2002.
Another way I sold Macs is to create ownership. Instead of using the words, "If you buy this" ... I would instead say, "Tomorrow morning when your using this ..." When I did iPod demos ... instead of spouting off about features, i would ask you what you had and tell you how the iPod was better simply by it's size and popularity.
These two principals are essentially the same thing. One shows people that others have bought it, one shows people they already own it they just need to get past the formality of a credit card swipe.