Never Mind I get It. also looks like it might be based off ADS-B feeds. Which also explains the lack of smaller aircraft. ADS-B is the new GPS based standard that is currently being set for a 2020 deadline for every aircraft in the sky to be equipped. Up until last year there were virtually none, besides a few guys in Alaska and oil rig helicopters.
These aircraft you are seeing are "NextGen" compatible. I'm actually surprised how many are already in some form of compliance according to that map.