They are all scams. They do offer you TV over the internet but it's largely useless TV like Israeli public television, Iranian channels, Hong Kong news, etc. you might get a few US television news feeds, like a local TV station that streams their newscasts repeatedly or a US weather feed, but you won't get anything interesting or useful like NBC or the History Channel.
These scammers make it sound like you're getting a replacement for comcast but in actuality, it's a ripoff full of useless channels.
there is a Firefox addon that give you 2800 internet TV channels for free:
»addons.mozilla.org/en-US ··· n/11200/
So what the scammers offer for $ you can get for free via Firefox.