Take a look at the above example. 

This particular site, when analyzed in Site Explorer, shows "No Data" for both backlinks and referring domains. 

How then can this domain have a UR of 9 and a DR of 14 without any data on backlinks?

Let's plug in the non-www version:

It turns out that this particular domain has 13 backlinks and 1 referring domain going to the non-www version. 

This explains why the domain has a value for UR/DR. 

Why are they different? 

Mozilla has a great article on why. I'll encourage you to read it. 

Some tips:

  • The next time you're analyzing your site (or another site) in Site Explorer, make sure you check both www and non-www versions to see if there are any discrepancies. 
  • If you still see "No Data" after checking both cases, please contact support and we'll take a look at it for you. 

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