VoIP telephone services in Western Europe leapt to just under 30 million consumer lines by mid-2008 – up from 20 million only a year earlier.
That figure has continued to climb and totalled 35 million lines at the end of the year, according to a survey by researchers TeleGeography.
The study into fixed-line VoIP usage also found that while the aggregate pace of growth across Europe remains rapid, fixed line market trends in each country are surprisingly unique.
Household penetration of VoIP telephony at mid-2008 ranged from slightly less than 50 per cent in France to less than 3 per cent in Spain.
In terms of annual subscriber growth rates ranged from 544 per cent in Portugal to a comparatively anemic 13 per cent in Norway.
TeleGeography analyst Patrick Christian said VoIP services are reshaping the fixed line market in Europe.
But he said regional market differences were were much in evidence.
"Europe may have a single market, but it’s far from common," he said.
"However, while the uptake of IP telephony services varies widely, VoIP has been a powerful spur to innovation, even in some countries with relatively modest numbers of VoIP subscribers."
This has taken the form of "incumbents" having to slash the price of traditional telephone services, to deploy higher-speed broadband networks and to introduce new video-over-IP services in the face of the challenge presented by IP-based competitors.
TeleGeography projects that the number of VoIP subscribers will continue to grow strongly, increasing from 35 million at end-2008 to 45 million by the end of 2009.