The cynic in me wonders if companies choose opt-out models because they think that a subset of their customers are not going to be bothered opting out.
A while back there was a lawsuit over one of the Canadian cable companies doing an opt out (negative option billing) and in general its not really considered a good business practice.
Of course they do, and many of them will make it as difficult as possible to switch without making it look like they're doing just that. Something you're taught is to make the "cost of switching" as high as possible.
I, personally, have continued to pay for a service I no longer used simply because it was such a pain in the ass to cancel.
