A second application under consideration in many trials is Home Shopping. In this application, the viewer can examine potential items to purchase (using video and/or still pictures), and eventually initiate an electronic transaction to purchase the items, which are then mailed to the person. It is believed that ITV can contribute significantly to the shopping experience compared to catalog shopping, because the items can be demonstrated, modeled, and otherwise promoted using the video and audio capabilities of the system in a manner analogous to home shopping TV channels. However, unlike home shopping channels, the viewer, not the network, gets to select the items for consideration. Catalog shopping and shopping channels combined had revenues of approximately $55 billion in the บ. ร. in 1994, so this market could potentially dwarf the VDO market.