More than likely that the door to door sales aren't employed directly with CF and on commission only so the competition for sales will be fierce. There's another ISP in London that does the same thing I think it might have been Hyperoptic.
Probably.
I was once called in as a consultant to sit-in on a meeting between Hyperoptic reps and a bunch of building owners they were trying to "sell" to.
It was clear the Hyperoptic guys had a well-rehearsed pitch which was fine tuned to their target audience (i.e. non-techie building management committees).
They had well rehearsed answers to the predictable questions thrown up by building management.
However they struggled with or rather tried to bluff and bluster they way out of technical questions.
For example, when I asked them how they could justify using CAT5e for the "last-mile" (i.e. basement area to residents flats), because for those residents on the upper floors this would easily exceed the CAT5e standards limits. (Their proposal was all their active kit was to be in the basement, so no fibre trunks between switches or anything like that).
So you can appreciate why I'm not a fan of the way these companies tend to operate.