Comcast Denies Own Traffic Prioritization → Am I wrong?

So please correct me if I'm wrong, but in simplistic terms...say I am on my pc watching a netflix movie, my roommate #1 is downloading some torrents (legal of course), roommate #2 is surfing...all which have maxed out my d/l bandwidth...and then roommate 3 fires up his Xbox to watch a movie via Comcast...Comcast is going to ADD enough bandwidth so he can watch his movie which is prioritized over the other things? Is this an overly simplistic view?

you nailed it cable convert.

Not overly simplistic but basically that's sorta what's going on.

As it stands now, instead of adding, Comcast just sends the data over an unused portion of the bandwidth your modem can do. If you have a 50Mbps plan with a D3 modem, it's the modem then limit the speeds to 50Mbps, it still has access to the rest of the bandwidth (100-300Mbps) and I guess if the Xbox Xfinity data is tagged as such, it just gets access to that other bandwidth that's not available to normal TCP packets.

While I agree this is "private" network, the only difference is below:

"ISP router" to CMTS to modem to my router to Xbox

vs

CDN to CMTS to Modem to my router to Xbox.

I'm sure Comcast doesn't have a bandwidth cap on their connection to the internet. AT&T/Verizon/L3 or whomever doesn't go, "Oh sorry Comcast, you can only use 50,000PB this month and nothing more or we'll charge you or cut you off" - In reality Comcast just pays for access to those backbones and if they want to dump 1Billion PetaBytes or 1 Thousand it doesn't matter. The router they have wont melt because it's doing more work either, it just might not be able to keep up. The problem is that if their customers use more data they'll have to upgrade the ISP Router(s) to handle the load and that's just not good business! Stock holders don't like seeing you spending money even if that means you'll have happier customers and therefore more willing to spend. Comcast rather getting by with what they have while charging more and therefore making a profit each quarter since costs hasn't gone up!

No CAP, but different economics. Instead of the monthly fee WE pay, Comcast has to pay capital for more for capacity growth - More QAM downstreams, more CMTS ports, more metro fiber, optics, routers, more backbone fiber, optics, routers, more interconnect ports, etc.