Actually it is:

customers that pay for cable + HBO > customers with internet only.

Hence why they have no current desire to alienate big cable to cater to the small number of users who loudly complain they can't watch HBO online when they want.

You are definitively right. But I meant to group the users with internet and cable in with the internet only users.

I doubt that inequality amounts to much. Outside of the tech crowd, if you have cable internet, you pretty much have cable TV. Their salespeople are relentless, and most people [in the US] really really really really like TV anyway.