So: type in any page URL and hit "Search". The results page returned contains the following (useful) information:

• The confidence level (more about this one below);
• The most frequent tags used for the page (you can exclude any or add your own to refine the results);
• The list of similar sites;
• Most frequent tags characterizing each page in the list;
• The similarity score (how similar each page appears to be to the base one, in %);
• The quick button to find similar pages to each one in the list.