The report from the Institute of Practitioners in Advertising, covering the third quarter of 2005, reveals that 60% of people in the UK now have digital television.
Young people are the biggest advocates of non-terrestrial television, with the under 16s accounting for 52% of the viewing figures.
Digital terrestrial platforms such as Freeview and FreeSat are the fastest growing segments of the market, reaching 20% of the UK population.
In terms of terrestrial channel share, Channel 4 has enjoyed its most successful quarter with 11% of the audience share compared to 10.5% in Q3 2004.
The channel's share has been boosted by hit US imports 'Desperate Housewives', 'Lost' and homegrown stalwart 'Big Brother'.
Meanwhile, ITV, BBC One, BBC Two and Five all lost share this quarter.
Lynne Robinson, IPA research director, said: "The non-terrestrial channels are growing steadily both in reach and share of viewing. Of the terrestrial channels, only Channel 4 is maintaining its share and patronage."
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .