Why should you care? There are plenty of web sites that do not conform to web standards, so why should you? If you're a business owner and you have a web site, there are actually many benefits to having a web standards compliant web site. In the competitive world of internet marketing, every little advantage you have helps.
How Web Standard Compliant Web Sites Help Your Business
Site Wide Look and Feel Consistency
When a web site is designed to web standards, there will be 2 parts to a web page. One part will be the actual structure and content of the web site, while the other part is the presentation. Because the presentation is separate, you can guarantee that all of the pages of your web site will look the same.
Less Bandwidth, Faster Loading
Once again, by keeping the presentation (found in the CSS file) separate from the web site content, pages will load faster because the CSS file only needs to be loaded once. In the days of yore, all of the text formatting had to be included within the web page, so it meant more data had to be loaded with every page view.
Better Search Engine Optimization
As newer internet browsers are developed, they will all be web standards compliant. This includes browsers on cell phones. Because a web standards compliant web site has presentation separate from content, the presentation files can be modified to suit web pages for print, on-sreen, and mobile viewing.
Technology today allows people with disabilities to browse the internet. If a web site is not compliant with web standards, the software a disabled person uses may be unable to render a web site. Being accessible is mandatory in many countries for government agencies.
Reducing dependency on any one developer
If a web site is developed with undocumented coding features, poor coding or coding hacks, then it could be near impossible for any one else overtaking the web site to work with it. Following standards-compliance in requirements documents is a very effective way to ensure measurable quality of the final product, the W3C being an impartial judge.
Because standards are very well documented, another person taking over some standard-compliant code can begin right away and will not need to become familiar with the previous developer's coding practices.