Use Google Analytics to monitor your site’s reach or any other analytical program but how you can compare sites which are not yours? Google trends enables you to see exact reach of any site and its comparative reach with other sites. Here is how it is.
Type or Paste the URLs (in following format) of sites you want to compare and see their reach. e.g.
engadget.com, mashable.com, techcrunch.com
Hit search trends button. You will get bars and graphs to show you how much reach any site has got in some countries including United States, United Kingdom, India, Canada, Indonesia, Germany, Australia, Malaysia, Philippines, South Africa.
The above comparison is of my favorite sites. This gives you which website is hitting more in any country related to any other similar site. If you have got some websites of your own or blogs, you can compare their relative reach in the same way easily using this method.