Another snapshot of the subtly significant semantics of Schema.org
The move represents a major advance in a campaign initiated in 2001 by Tim Berners-Lee, the inventor of the Web, to enable software to access the meaning of online content—a vision known as the "semantic Web." Although the technology to do so exists, progress has been slow because there have been few reasons for Web page operators to add the extra markup.
Schema.org may change that, says Dennis McCleod, who works on semantic Web technology at the University of Southern California. By tagging information, Web page owners could improve the position of their site in search results—an important source of traffic. "This will motivate people to actually add semantic data to their pages," says McCleod. "It's always hard to predict what will be adopted, but generally, unless there's something in it for people, they won't do it. Google, Microsoft, and Yahoo have given people a strong reason."