Backlinks enable you to keep track of other pages on the web that link to your posts

In the search engine optimization (SEO) world, the number of backlinks is one indication of the popularity or importance of that website or page (though other measures, such as PageRank, are likely to be more important). Outside of SEO, the backlinks of a webpage may be of significant personal, cultural or semantic interest: they indicate who is paying attention to that page.

Most commercial search engines provide a mechanism to determine the number of backlinks they have recorded to a particular web page. For example, Google can be searched using link:wikipedia.org to find the number of pages on the Web pointing to http://wikipedia.org/. Google only shows a small fraction of the number of links pointing to a site. It credits many more backlinks than it shows for each website.

Yahoo!’s Site Explorer is a favorite method of obtaining the number of backlinks on a site, because this tool shows a larger number of the actual backlinks than any other tool.

http://siteexplorer.search.yahoo.com/