Valid web sites... why have those? Site works well and shows well even if it isn't a valid code... why would I take my time trying to make a valid web design? Why does it matter?
Yes, this blog isn't a valid to standards (W3C Validator) so I don't have much to brag about on this site...
Anyway it would be a good idea to have a valid web site because then it would have a greater chance of success with SEO (Less bytes for the spiders to travel through), the validity of the site is also the image of the designer... a good web developer/designer would make a good site, true? The quality also resides in the validity of the site.
Validity of the site also increases the chances of the site being compatible with the dreaded IE as well as in Firefox, Opera, Safari, etc... Although Internet Explorer 7 has improved a great deal from Internet Explorer 6, it is nowhere close to Firefox or Opera.
The advantages of having web sites that are up to standards are greater compatibility with other browsers, a good image of the web designer/developer, better SEO, decreased loading time/decreased bandwidth,
How is validity of the site good for your SEO? Let me try to explain it this way, lets say you have a site in which you use the <p> tag, you know that in order to have a valid file you need to close that tag by using </p>. If you don't close it and put the <p> tag after the paragraph you obviously see everything correct on the browser but when the spiders from search engine come in they see a paragraph within a paragraph and its all a paragraph... like the following would be how it would look on a browser.
This is a paragraph<p>
This is another paragraph<p>
The following is how the spider sees it...
This is a paragraph<p>This is another paragraph<p>
The spider would either render the page as a spam and nothing worthy of the search engine or apply bad keywords to the entry. You certainly wouldn't like that and that would be a great disadvantage to you, as a web designer/developer.
Of course, making files valid is not the law it is merely a designer's/developer's choice, but I highly recommend it.
