Its is a misconception when people question the viability of semantic technologies by saying that "it isn't possible to convert all the data to RDF format?" In reality , it is not true at all. Again, it is important to keep in mind that we are not talking about semantic web, we are talking about semantic technologies. It can be best explained by talking about how Yahoo Search Monkey is using RDFa (RDF in Attributes) to enhance search results more useful and visually appealing. It is just one of the simple examples but it can hopefully answer the sceptics. It can be a boon to small businesses who can drive more traffic to their web sites. SearchMonkey looks for special data inside websites, based on a standard called RDFa. Your website should include this data so it is available to Yahoo as they crawl and index your site. This way your business information is available to any developers who build SearchMonkey apps, and you will show up with enhanced results as this gets adopted over time. The SearchMonkey platform has three main components: - "Site owners share structured data with Yahoo!, using semantic markup (microformats, RDF), standardized XML feeds, APIs (OpenSearch or other web services), and page extraction. -Third party developers build SearchMonkey applications. -Consumers customize their search experience." RDFa is a way to encode data within HTMLand XHTML pages which helps people and machines to embed structured data within HTML and XHTML pages. The underlying representation of RDFa is RDF because it is flexible enough to let publishers build an devolve their own vocabularies. You can see Search Monkey in action by clicking on this link http://www.yelp.com/search?find_desc=nobu&ns=1&rpp=10&find_loc=San+Francisco%2C+CA#find_loc=new%20york
You can see the enhanced quality of the result "nobu new york restaurant". You will probably realize that you have many using Semantic technologies without even realizing it.