"I don't disturb you when you're working, do I?" snaps stand-up comic Jimmy O at a Comedy Store heckler. "I don't come in the alleyway and knock the cocks out of your mouth."

Having honed his craft on the Northern club circuit, Jimmy is attempting to move into the lucrative cruise ship business where the atmosphere is a lot less adversarial, but the audience is older and more conservative in its tastes.

"I'm not happy with any shades of blue," warns Richard Sykes, cruise director of the Ocean Countess as she navigates the Hebrides. "Also, please don't abuse the passengers."

Jimmy will have to tailor his material accordingly. But the question is, will he have any material left?

Funny Business followed Jimmy on-board his new, floating stage, as well as exploring the phenomenal growth of an industry in which variety acts - and comics in particular - are in big demand.

The programme interviewed bookers, agents and veteran performers such as Tom O'Connor and Nicholas Parsons, who all expressed enormous enthusiasm for this once-derided but now burgeoning home for live entertainment. Meanwhile, they acknowledged the fundamental problem facing the industry - how to appeal to a younger, edgier market without alienating the established clientele.

Hired to test the waters but without making waves, so to speak, Jimmy O is on something of a hiding to nothing, but his act doesn't do him any favours. Witty, personable and charming among the passengers on deck, Jimmy sacrifices all three to a stage persona that isn't so much slow burn as catatonic.

He gets laughs, but not many, and cruise director Richard is further enraged at being short-changed by 25 minutes for a 45-minute slot. Which, given Jimmy O's speed of delivery, translates into about ten minutes of actual material. His booking is immediately terminated with a ruthlessness Captain Bligh would have approved of.

'Cruising is the gig to have,' says black American comic Percy Crews 2, 'Cruising, now, is like the new Las Vegas.' No, he's not talking about searching for an anonymous fuck; the third and final episode of BBC2's doc series about the comedy industry focuses on the lives of cruise-ship comedians, and the big bucks they can earn at sea.

Through interviews with old-school entertainers like Nicholas Parsons and Tom O'Connor, we learn what's required to keep the passengers amused, and how being aboard with your audience means you're on stage even when on deck. What's the secret? 'It's getting as old as most of the passengers,' jokes one-man-band performer Bruce Thompson. But the cruise industry has inevitably changed over the last 30 years. Those loyal older passengers still want the safe veterans, but a new younger audience are coming aboard, and that's where Percy Crews 2 comes in, playing edgier, late-night shows on the more party-centric ships.

But we know this goes on, and if we didn't, it's not exactly a huge surprise. Interesting enough, but not the eye-opener we were hoping for.

This temporarily shelved documentary series reveals a side of some famous comedians that's rarely seen, largely because they'd rather it wasn't. It peeks into the murky world of corporate events, where a big name can earn more in a night that a struggling circuit comic does in a year. The pros' wildly varying attitudes to these gigs, and to starring in adverts, are fascinating - as is how managers earn comics huge sums for their regular work. Beneath the wry tone are serious questions about how principled artists should be.

"Cruising is like the new Las Vegas," says one comedian of the $3 billion industry. This final episode of the series about how comedians make money from corporate gigs follows Wigan comic Jimmy O as he makes his debut at sea. Comics may have turned their noses up at cruising in the past but with the potential to treble their earnings, many are now taking to the waves. Indeed, Tom O'Connor says that 40 per cent of his income comes from working on the ships.

The return of a series that was binned after one episode last month - up against Africa on Wednesday night, it died on its backside. Now, in a less high-profile slot, it continues its exploration of the commercial end of comedy by looking at how managers and agents ensure that the nation's top comics earn pop-star bucks. Rhod Gilbert and Jo Brand, whose extremely candid interviews helped to make the first episode so engrossing, are back along with Eddie Izzard and David Baddiel.

'Look at the bloody size of it!' marvels Peter Kay as he runs on stage at the O2. It feels a little disingenuous, because Kay is arguably at the front of a pack of comedians who have been aiming this high from the start. The second part of this fascinating three-part series examines the process behind these startling new comic trajectories. Via a dig around in the BBC's written archive (Frankie Howerd was on 80 guineas a series) and Frank Skinner's brush with pay-related tabloid infamy, we reach the present day.

Comedy historians will probably dub our era The McIntyre Ascendancy. But has edge and artistry been lost as careerism wins the day? Or is it naive to think that stand-up was ever about anything other than a drive towards commercial success? Reassuringly, Mark Thomas is on hand to suggest than comedy has 'fallen for the capitalist concept of endless growth'. But the hyper-competitive Comedy Store bearpit we visit at the end suggests that many young comics still think there's a pot of gold at the end of the rainbow.

Eddie Izzard crops up in the delayed second episode of Funny Business, in which the machinations of comedy agents and promoters fall under scrutiny. But the focus is largely on the rise during the last 30 years of stand-ups earning ludicrous sums of money from sell-out mega-tours, thanks in part to the heavily monopolised likes of Live at The Apollo.

The most fascinating portion of the programme by far is when a comedy historian delves into the BBC's Written Archive - housed in a modest bungalow in Berkshire, believe it or not - to contrast the earnings of today's top comics with those of the heroes of yesteryear. One particularly sobering revelation is that when Ernie Wise died, he left behind an estate worth over just half a million pounds. In 2011 alone, Peter Kay earned an estimated take of over £20 million from touring and DVD sales. As the formerly funny Boltonian might himself remark, what's all that about?

All performers, and especially comedians, would like to have credibility. This was the subject of Funny Business (BBC Two), a show in which I took a personal interest, because I once harboured the illusion that I could do after-dinner speeches and commercials and thereby pick up some easy money.

Until recently, straight actors lost credibility if they did commercials. Sir Laurence Olivier did a Polaroid commercial, but only on the understanding that it would never be screened in the UK. Today, however, George Clooney hustles coffee and Brad Pitt barks for Chanel No5. The money might go to charity, but it still counts as a fast buck. Nevertheless, the actors get away with it.

For the comedians it has always been a hard choice. A commercial will look like slumming unless it is funny enough to be thought of as part of the comedian's repertoire. Another question mark hangs over the corporate event appearance, where months of big bucks can be earned in a single night. But people who haven't paid to see you, and who are sitting at round tables which ensure that many of them are facing the wrong way, are a soul-destroying prospect.

Intelligent comic operatives such as Barry Cryer, John Lloyd and John Cleese were united in the opinion that the business opportunities form part of the career. But I can say from experience that it hurts when it goes wrong. I once did a big, expensive set of plugs for Australian Telecom in the very year that their opposition came out with a better product. And the money wasn't all that easy. There is a small hill of red dirt somewhere near Alice Springs that is flatter now because of the number of times I had to walk up it.

This three-part documentary series, narrated by journalist Eddie Mair, looks at the 'darker', money-making side of the comedy world.

The first episode looks at how many comics, in particular stand-ups, make money by performing at corporates. It shows performances from The Real Variety Show where comics play in front of business people keen on booking them for events.

Then it follows the world of adverts, discussing comics like Mark Arden and Stephen Frost (who did ads for Carling Black Label) to QI creator John Lloyd (who first met Alan Davies when Lloyd directed ads for Abbey National.) I know there's a history of comics doing adverts - despite the public outrage at Mark Watson a few years back - but I was suprised at the frequency of appearances. Most of the ads were produced 'before my time' as it were, so were quite shocking in a way. Stephen Fry and Hugh Laurie advertising tobacco?

It's definitely a growing trend, though; if you're feeling bored, you can play a little game where you try to spot how many times in a three-minute period you can hear the voice of Hugh Dennis.

Off all the people on Funny Business, though, the most interesting was Rhod Gilbert. Rhod explained how one corporate gig resulted in him sacking them off altogether, and how he justified doing adverts for the Welsh tourist board because he was promoting a country rather than a product. There were also interesting contributions from Mark Thomas, who attacked just about any involvement of comedians and advertising. The only advertising I can think that he has been involved in was with early episodes of The Mark Thomas Comedy Product, which were sponsored by small independent shops - like a gentlemen's hairdressers and a record shop.

Funny Business declares that the problem with advertising is that there's no funny ads. I can't help but think the problem's that there are ads to start with.

Funny Business, narrated by Radio 4 newsman Eddie Mair, showed us what comedians were doing when they weren't monopolising television - to wit selling their souls at lucrative corporate dinners. Here was the menu - half an hour of Michael McIntyre for £40,000, Ricky Gervais for £25,000. Lesser lights got less, but how could you resist? You were right there in the shop window prostituting your art. One lavish event, the Real Variety Show, with its audience of hardnosed business types, could land you 30 other corporate gigs. Jo Brand and Arthur Smith bared their shame but took the money. Everyone had experience of being ignored on stage. Rhod Gilbert was visibly distressed as he relived the night he found himself talking to the back of Sir Alex Ferguson's head at a footballers' beano in Mayfair.

It was revealing but long-winded, and I found myself wondering how much Eddie Mair was getting paid as we drifted into the overvisited realm of vintage advertising with its (yawn) clips of Fry and Laurie selling cigars and John Cleese being zany in the service of Schweppes. "Wherever you look now, money's spoiled it," said Cleese from his Monte Carlo apartment.