On-demand viewing is encroahing traditional TV programme schedules, according to research by Tiscali.

In its TV Trends Report 2008, the internet service provider (ISP) found that that over a third of the 1,760 people surveyed were now using on-demand services instead of traditional TV schedules.

Nearly two-thirds (64 per cent) said that this was because traditional schedules were too restrictive, with four in 10 saying they wanted more flexibility.

Just over half said they used the flexibility of on-demand services to watch a missed programme and two-fifths said it was to overcome schedule clashes.

Although new internet TV services such as the BBC iPlayer, ITV.com and Joost, have come into the market this year, nearly two-thirds of viewers still prefer to watch on-demand programmes on their television sets. Only a third said they watched these programmes on their PC.

On-demand viewers are also younger with nearly half of 16 to 34 year olds saying they have viewed content compared to just over a fifth of over those over 55.

One of the main obstacles to watching TV on-demand is perceived cost; over half of people surveyed said this put them off using the services.

Other people are unware that on-demand services exist (31 per cent) but despite this eight in 10 said the new way of watching TV would see the end of traditional TV schedules in 10 years.