We used to use Google's PageRank values in our system but as of October 6 2014 following Google's John Mueller announcement that "We ll probably not be updating it [PageRank] moving forward." this algorithm has become outdated and generally useless for building metrics on. It is still used to some degree within Google's systems but no-longer reflects changes to the public.
Given that this is no longer a valid usage for determining website information, we have decided to drop the value it used to add.
We now aggregate all our information and use the Statvoo Rating System instead.