Check out these questions and their answers:

There are no tags or keywords on my website according to UrbanData. Why is this?

To have sites or tags appear you have to indicate to our site what they are. Keywords or tags are words that tell something about the subject of your site and your pages. Search engines like Google use these together with the content of your page to find out what your website is about.
To make sure you have keywords appearing in UrbanData, you have to place some HTML (the markup language your website was built with). This code is very simple: 


	<meta name="description" content="A short description about your website." />
	<meta name="keywords" content="keyword1, keyword2, keyword3" />
Change the keywords to words that describe the content of your website and the description to a description relevant to your website. Put this code after the </title> in your homepage.
If you are using a CMS or blogging system like Wordpress there are usually editors to change this information. For Wordpress you should consider reading up about and installing the All in One SEO Pack plug-in.

My website report shows there are no Related Sites at this moment; can I do something about that?

If your website report shows no Tags and no Related Sites, you have no 'meta tags' in the homepage of your site. To add those, please check the previous question in this FAQ.
If you see Tags in your report but no Related Sites, we could not match your site to other sites. Maybe your tags are too specific or there are too little of them. You can add more tags to your site easily, please check the previous question to find out how.