The amount and distribution by time of day of TV viewing, as well as the PSB group viewing shares have remained notably stable over the last ten years in which the major shift from analogue to digital transmissions has occurred and timeshift/catch-up viewing has become commonplace.

The topline trends nevertheless mask significant age-related under-currents of change, which have seen a large loss of younger audiences and sharply ageing profiles for BBC1, BBC2 and ITV.

Whilst the more youth-oriented Channel 4 has avoided the ageing profile effect, it faces its own challenge of averting audience decline, as it finds itself at the sharp end of change among younger adults and faces declining support among older viewers.

Channel 4 enjoyed a bumper year in 2012 with regard to delivering its public service remit, epitomised by the London Paralympics

Public service successes notwithstanding, the continuing decline in main Channel 4 audience share post digital switchover is not being fully compensated commercially by large gains across the rest of the Channel 4 portfolio

Overall, we expect group revenues to remain quite stable in 2013 and 2014, but current record levels of investment in programme content origination have yet to bear fruit in terms of strong returning series

The development of the Digital Britain infrastructure, introduction of tablets, increasing connectivity of TV sets and launch of on demand OTT services over the internet have greatly intensified interest in connected viewing and its impact on the traditional broadcast model No single source of audience measurement for viewing of long- and short- form video content across all screens yet exists, though current market data suggest that connected viewing occupies a c. 8.5% share of total viewing across all screens By 2020, we project the connected viewing share of total viewing across all screens will reach 20%, with tablets being the primary drivers of growth, in part incremental and in part substitutional to viewing to the TV set, where we expect the connected viewing share to remain under 5%

Channel 4's digital diversification strategy is a topic we first considered in 2002. At that time, we urged Channel 4 to husband its resources to meet its public service remit and maintain audiences on its terrestrial service, rather than diversify into new digital satellite channels. If anything, the progress of time has reinforced our conclusion that Channel 4's digital diversification strategy is risky. The risks for Channel 4 are greater than for the BBC, since Channel 4's public service remit is funded by advertising alone

On 27th July the BBC will open access to the iPlayer to UK internet users, en route to a hard launch later this summer. This PC-based application allows the user to download BBC TV content after broadcast to view on the PC for a limited time, and provides a TV-like display on the PC. Delays to the launch will mean the iPlayer enters a field already crowded by other broadcasters, including Channel 4's 4oD service, ITV's broadband portal, Sky Anytime, as well as content aggregators such as Joost and Babelgum (both currently in beta)