what is meant by demonstration effect?

It is one of the marketing strategies. Parking two-whellers for sale at the entrance of dealer showroom is to give demonstration effect of the same.

hi! it is actually the urge to buy things when you see somebody else using a particular product. Supposing your friend has a hi-tec gadget, though you are not too inclined to buying it, you go for it. This is called demonstrtion effect.