The best SEO is a website that meets the needs of its target users effectively. To do that you need to have a site that has something in it that people can use, want, or need. This is value and its the most important thing. It can be anything from good articles to entertaining video or a useful download. Tags support good content but cant replace it for SEO. If the content is good enough no tags are needed. Trust me when I say, if your site has something, anything people want or need, that they can't get just anywhere, your site will do well in all regards, tags or no tags. If your site is boring and has no value it will fail, tags or no tags.
