PCs – they can do so many things, but are so complex. Appliances do ONE thing, and do it very well. There are spam filtering appliances, search engine appliances from Google, and etc.
Cnet writes Costs of hardware have been pushed down persistently for years, making appliances cheaper to buy. Also, standardization is increasingly common in the IT industry, affecting everything from chips to software.
Though far from widespread, the practice of selling boxes that combine both hardware and software engineering, instead of only software, has a bright future, proponents say. Some predict that appliance design will become a part of more and more applications as the approach catches on.
The main selling points behind an appliance are cost and speed. A device used for a specialized purpose can be easier to install and maintain than component pieces, industry executives said.