In respect to CD duplication, the 1st thing that comes to mind is music; however the fastest growing area is data. Today there are businesses that put their catalogs, instruction manuals, press releases and other data into a CD-R format for distribution. Most of these businesses have their CD-R's duplicated by an outside vendor. Companies that have discovered cd duplicators have reported (1) that they have been able to recapture the cost of the equipment in just one or two 'runs' thanks to the cost of blank media and (2) more importantly have reported that the "killerapp" of owning a duplicator has just not become a cost saving factor, but the opportunity to make changes 'on-the-fly' (pricing, sku, picture changes) immediately without dealing with the time delay that occurs with outsourcing.
In respect to DVD duplication, many of the things that ring true for CD exist here as well, albeit with larger file sizes & of course video. One thing to keep in mind - As the installed base for DVR's grows, & consumers become aware of our DVD duplicators, this product may very well become an important part of a household's technology arsenal.