A means of distribution. It is the reverse of
shoplifting, where something is taken from a store without the store's knowledge. Droplifting involves bringing merchandise into a store without the knowledge or consent of the store. The product is then purchased or possibly stolen by the normal patrons.
Why droplift?
Well, in the case of CD distribution, it is a novel way to get an illegal product into the hands of the CD buying public. The folks at http://www.droplift.org/ wanted to distribute their CD "The Droplift Project" which is made up of songs that contain uncleared samples of other songs or sounds.