An independent report into the performance of the BBC's four digital channels – BBC3, BBC4, pre-school kids' offering CBeebies, and CBBC (targeting older children) – has concluded that first two provide "poor value".

The review, commissioned in April by Tessa Jowell, government minister for culture, media and sport, was led by Patrick Barwise, professor of management and marketing at London Business School.

Barwise dismisses BBC3 (which targets viewers in the 25-34 age range), and the culturally oriented BBC4, as "poor value" in terms of viewing numbers.

However, he concedes that the stations have "largely met their remits" – a conclusion that suggests the corporation's marketers should be indicted rather than its programme-makers.

The two new channels have made only a "limited impact" on their commercial rivals, Barwise says, with a "modest" contribution to digital takeup by consumers. He notes that 80% of the BBC's resources in this area target viewers under 35 years – whereas future takeup depends largely on older viewers, particularly those aged 55+.

The report advocates broadening BBC3's appeal beyond the 23-34 age bracket, its present narrow range acting as a "creative straightjacket". Overall, the BBC should "keep promoting digital television [and] focus on the extra choice it provides (including digital radio) rather than on the supposed joys of interactivity".

Barwise then ventures onto the shifting sands of culture, suggesting that BBC4 – seen by many discriminating viewers as a beacon of light in a fog of makeover mediocrity – should broaden its appeal and transmit fewer arts programmes that "virtually no-one watches".

The government's choice of a marketing guru (who is also an audience research advisor to Ofcom) to lead the review suggests that viewing numbers and demographics – rather than quality programming are the criteria by which the public service broadcaster is being judged.

As some cynical observers of the media scene have pointed out, it is not without significance that the review was commissioned by a department whose name combines the oxymorons 'culture' and 'sport'.

A similar review of BBC digital radio has been conducted by Tim Gardam, former director of television and director of programmes at Channel 4. The report will be published next week and cover the new stations 1Xtra, BBC6, BBC7, BBC Asian Network and Five Live Sports Extra.

Data sourced from mad.co.uk and other origins; additional content by WARC staff