Search engines get smarter as SEO plays a larger role in the online industry, and as people find ways to trick robots just to get high ranking for their websites. A few years back, Google and Yahoo launched Microformats that handle the ambiguity of a website structure. Some websites have unstructured data that make search engine robots confused – often miss out what the the site’s niche really is. It is a technical misunderstanding between search engine crawlers and the data structures of a website.
Traditional content management systems are monolithic beasts. Just to make your website editable you need to accept the web framework imposed by the system, the templating engine used by the system, and the editing tools used by the system. Want to have a better user interface? Be prepared to rewrite your whole website, and to the pain of having to migrate content between different storage systems.
The concept of a semantic web, or at least of a semantically structured web of knowledge, has been around since the late 60s. It was brought to the forefront of the layman’s consciousness by Tim Berners Lee, inventor of the world wide web, speech at TED 2009 in which he got the audience to chant the rallying cry of the Linked Data evangelist “Raw Data Now”.
RDFa Developer is an extension for firefox that lets you visualize the triples of a web page, reports common problems, and allows you to execute SPARQL queries directly on the RDFa content. (Version 1.1 working for Firefox 7)
Rich snippets -- we see them everywhere in the SERPs, with some verticals having a higher abundance of them than others. For the average searcher, these rich snippets help show them what they're searching for is within reach on a particular site.