The channel, once home to popular hits such as Two Pints Of Lager And A Packet Of Crisps, Little Britain and The Mighty Boosh, as well as critical successes such as Ideal and Pulling, is now struggling against the likes of E4 and ITV2, with audiences across all genres rarely reaching higher than 750,000 viewers in overnight figures, and home-grown comedy struggling to hit the 500k mark.
At the time of writing, the free-to-air channel's biggest audience pull is American import Family Guy, which drew a channel peak audience of 731k for its 11:20pm episode on Thursday night. 10pm repeats of EastEnders also perform relatively strongly, attracting 797,000 viewers on Wednesday and 763,000 on Friday.
However, original comedy is floundering in the face of no clear competition whatsoever: the third episode of new sitcom Dead Boss, which has attracted mixed press reviews but high-profile celebrity fans such as Sarah Millican, broadcast on Thursday to an audience of just 421,000 viewers, down from 500k and 480k for the double-bill opener last week.
Similarly, stand-up and sketch comedy showcase series Live At The Electric opened with just 410,000 viewers. Episodes since (the fourth was broadcast on Thursday) have performed so poorly so as to not even chart in overnight ratings figures.
Topical stand-up series Russell Howard's Good News, currently in its sixth season, is now the channel's sole strong British comedy, regularly attracting between three quarters of and one million viewers. (Against Euro 2012 football coverage on BBC One, however, the premiere broadcast of last week's episode achieved a record series low of 501,000 viewers, just 2.02% of the entire television audience.)
Much of the slide in the channel's fortunes appears to coincide with the arrival of Zai Bennett as channel controller in early 2011, and his cancellation of a raft of shows to "change direction" for BBC Three's comedy output. Speaking at the end of May to in-house magazine Ariel, he said: "One of the things that I really concentrated on when I joined included getting the comedy sorted out," but added that "you won't really see that on air until this autumn."
A number of commissioned British comedy writers have now expressed to the British Comedy Guide that they feel "complete disillusionment" with BBC Three, believing that Bennett has "no clue" what he is doing with the channel other than trying to "stamp his own mark".
That "change in direction" was spearheaded earlier this year by comedy-reality series World Series Of Dating - which opened with a mere 320,000 viewers and slumped from there, eventually being shifted to a graveyard midnight double-bill slot for the final 2 episodes of its 8-part run. The channel has since ordered a sketch show/reality format cross-over pilot, entitled Boom Town.
In 2011, the first series of Adrian Poynton's sitcom White Van Man - which had been lined up by Zai Bennett's predecessor Danny Cohen - achieved a series average of three quarters of a million viewers (with consolidated figures of more than 2 million across the run) for its premiere transmissions in March and April of that year: the second series, broadcast during February and March this year was moved to a different day and time slot by Bennett's scheduling team, and promptly dropped a near unprecedented 300,000 viewers, to just 480k for its opening episode.
The series dipped to just 340k in the middle of the run, and averaged 403k over the six episodes. It has since been cancelled by Bennett but picked up for a US adaptation by the Disney-owned ABC network. Meanwhile, repeats currently ongoing on BBC One - now controlled by original White Van Man commissioner Danny Cohen - in a post-EuroMillions 11:30pm Friday Night slot have achieved 849k (original Three audience: 480k) and 1.06 million (440k).
On the subject of Danny Cohen's scheduling the series for repeats on the corporation's flagship channel just weeks after Bennett had cancelled the show, one BBC employee told British Comedy Guide: "This cannot be seen as anything other than a big 'fuck you' to Zai. Having originally commissioned it, Danny saw what a great show White Van Man was, and how much potential it had."
As further illustration of Three's decreased audience across the board, White Van Man Series 2 was doubled-up in broadcast slots with new sitcom Pramface, the opening episode of which achieved an audience of 469,000 viewers (1.37% audience share) - a figure now considered "impressive" for the channel.
To contrast with figures more directly pre-Bennett, big hitters such as Two Pints, cancelled in 2011 after 9 series, had been increasing its audience from previous series, with an average reach of 2.5 million viewers per episode (across premiere, iPlayer and repeats).
Other cancellations have included How Not To Live Your Life (right), Ideal, Lunch Monkeys, Mongrels, and teen sitcom Coming Of Age - the latter of which was consistently a top-10 rated iPlayer programme, with a weekly audience of 1.8 million.
However, it is not merely comedy - for which exceptions can be found throughout BBC Three's history - that is suffering. The opening episode of a new series from Cherry Healey on Wednesday evening achieved 478,000 viewers. Films such as those in the Pirates Of The Caribbean series now appear to be the channel's biggest draw, and yet still only achieve figures circling the 1 million mark. Whilst many figures are not necessarily poor individually, they do appear to represent a downward trend in the audience for the channel as a whole.
More subtle changes, such as the replacement of a number of the channel's continuity announcers, have also drawn criticism from viewers, and BBC Three will soon be joining the corporation's great London exodus with a move to new offices in Salford, Greater Manchester.
A BBC insider and keen industry watcher told us this week: "Personally, he's a nice bloke and good to have a pint with, but professionally... Well, at one recent event he spoke at length about 'not patronising' the predominantly youthful Three audience. He then proceeded to commission the most patronising guff, written and produced by people pushing fifty from both directions who seem to know nothing about their subject matter, alongside dreadful over-produced 'documentaries'. Sometimes BBC Three does as badly as 0.7% reach now - Danny Cohen had been building up respect for the channel, so it's really sad to see it in this shape after barely 15 months."
The insider continued, pointing out that Bennett's promised "sorting out" of comedy has not yet come to fruition: "Having now set himself an autumn deadline for improvements to materialise, it may now be a question of whether the audience figures will rise, or Three gets its third controller in as many years."
Upcoming BBC Three shows include Jack Whitehall's Bad Education, Cuckoo, Some Girls, and pilots such as IED and Tom And Jenny. Further series of a number of programmes, including Pramface, are also in production.