In the words of the product description:
The iJohn digitizes both liquid and solid waste products and sends them electronically to a central facility for processing and disposal. Because of the high level of redundancy in the waste stream it can be compressed to a small fraction of its original size resulting in transport costs far lower than with traditional methods. And because the waste products are in digital form they can be easily routed to alternate destinations based on available capacity, labor costs, and the regulatory environment.
"Consider a spherical bear, in simple harmonic motion..." -- Professor in the UCB physics department