CBS All Access"
It's not really obscure. They already have about a million subscribers and it may already profitable, though they don't seem to have released individual numbers for the HBO and CBS streaming services so it's impossible to tell. The new content will almost certainly help increase those numbers.
For decades there have been people saying that wanted cable TV to let them buy individual channels instead of a bundle because the increased cost for the handful of channels they want would still be cheaper than the bundled price for 300 channels that they don't want. This gives them what they asked for and it turns out that about a million people weren't just talking out of their ass.
It's pointless to talk about numbers we don't actually know so I'll just address the fact that CBS is not a cable channel, they are a national network of OTA TV stations that anyone in the US can already watch for free. You can even buy a cheap USB TV tuner and record it if you want to watch something later. The only way I'd ever consider paying for it is if I were living abroad but they say they restrict access to only the US and I don't know how much VPN wack-a-mole they do.