I do not live over there, I have never seen a Vonage or Magic jack or any other VoIP service ad on TV in the UK, ever.
Vonage *are* advertising on UK TV. Hardly the carpet-bombing the OP suggests is the case in the US, but they are doing something.
It is quite a different market here. I can get POTS services over the same copper from, I'd say, about 5 different companies. Maybe more, I have not counted. I guess the competition already available on the copper would largely preclude anything but the cheapest VoIP service.
For UK national calls, which pretty much all the POTS providers are offering for "free" (read "bundled"), I tend to agree - especially given that the POTS providers who *aren't* BT (Residential) are largely having to lease at least the last mile copper from BT (OpenReach). The Vonage TV ads that I've seen in the UK are pitched at offering cheap / free / bundled international calls, and the target market for that I believe is both different and smaller. Regards, Tim.