Comcast is more or less limited to customers where it currently has cables in the ground - which is a subset of the US population. To grow its customer base, i

Comcast is more or less limited to customers where it currently has cables in the ground - which is a subset of the US population. To grow its customer base, it has to lay more cable, or enter into agreements with existing cable operators. Netflix is present in around 200 countries around the world, some of them with significantly higher population than the US, and is available to anyone with an internet connection of some description. It's very possible that the valuation is in large part because of this potential.