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.

Astounding news as BBC2's new three-part series Funny Business revealed that Michael McIntyre commands a higher fee for a corporate gig than Ricky Gervais (told you you should've agreed to do the dance, Ricky.)

We also met the promoter who gave Jimmy Carr his first-ever paid booking back in the days when Jimmy's career was more Haven holiday park than tax haven. Sadly, the promoter didn't elaborate further so we were left wondering a) how much Jimmy was paid and b) how much he was left with after tax. My guesses are a) around £50 and b) around £50.)

The corporate gigs are not for everyone, though. Following a particularly soul-destroying half-hour set at one PFA annual dinner Rhod Gilbert vowed never to do another. 'I just remember seeing Alex Ferguson's back as he talked to someone during my act.' Could've been worse, Rhod. Fergie could've demanded an extra seven minutes.

Your average comedian can earn serious money these days. Your very good one can earn a fortune. Michael McIntyre's latest tour, for example, netted him £21m. But there's more than one way for a stand-up to rake in the cash.

As we'll see in BBC2's new documentary series Funny Business, corporate gigs and telly commercials are huge earners. You want Jason Manford? That'll be 25 grand.

With contributions from the likes of Jo Brand, John Cleese and Rhod Gilbert, the programme also poses the inevitable awkward question. Namely, is a comic selling their soul by doing this stuff? Some people clearly think so. Carmarthen's Rhod Gilbert points out that the only ad he's ever been willing to do is for Visit Wales.

Mind you, I personally reckon he sells it better, sloganwise, in a clip from Live At The Apollo: "Wales is all right! It's not s**t anymore! We've done it up!"

Anyone who works in an office will have had the experience: an awards bash for people in your sector, a hotel ballroom, rubbery roast chicken - and up on stage a half-known name from the comedy circuit making ill-informed cracks about your business and looking as if he can't wait to collect his cheque.

It needn't be such torture; in fact, some comedians make an art form (and a packet) out of such well-lubricated corporate gigs, as this three-part series discovers. Among those recalling the pitfalls when comedy and commerce collide are John Cleese, Rhod Gilbert and Jo Brand, while RT's own Eddie Mair narrates.

'We've all become Thatcher's children,' reckons jobbing comic Hal Cruttenden, who merrily makes something like two grand a gig on the corporate circuit. Mark Thomas, naturally, begs to differ. And that's the beauty of this opening episode of a three-part documentary: it takes a very timely look at the business of comedy - bigger than it's ever been, surely - from all sides. It's also very funny, especially when established comedians, who undoubtedly deserve credit for even discussing the issue, grapple with their consciences as they explain themselves for doing what some might regard as selling out. A corporate gig is good practice for working a tough audience, says Jo Brand; doing adverts (or 'content-driven engagement platforms', as one suit now calls them) buys writing time, protests John Cleese; Rhod Gilbert, meanwhile, has bailed out of them altogether, his nerves and self-image unable to take it any more. The astronomical fees may simply reflect supply and demand, but it doesn't make the reality any more edifying. Engrossing, nonetheless.

In Funny Business (BBC2), the first of a series, Eddie Mair narrated an investigation into the ways in which standup comedians can make big money, none of which is by telling jokes in comedy clubs.

Appearing in adverts is one way, but many comics find selling stuff on TV to be inconsistent with either their morals or their sense of humour. Not that many, actually. Less objectionable is the corporate gig. You're just doing your act, albeit in front of a room full of company managers for an obscene amount of money. Ricky Gervais gets £25,000 for a 20-minute corporate set. Michael McIntyre gets £40,000. It's not surprising that up-and-coming comedians on corporate booker Jeremy Lee's roster fall over themselves to appear in his annual Real Variety Show, essentially a huge audition for an audience of events company managers. Again, it's just a gig, you end your set with the punchline: "I'm available for bookings, and I also host!"

A lot of comedians won't touch corporate gigs either, but not necessarily for the reason you might think. "I doubt there's one comedian in the world," said Arthur Smith, "who hasn't died on his or her arse at a corporate gig."

Jo Brand finds them bracing - "If you do corporates, you get the message that not everyone loves you," she says - but Rhod Gilbert still gets heart palpitations just driving by the venues of old corporate failures. It may be filthy lucre, but it doesn't sound like easy money.

Rhod Gilbert: my heroes and heroines

The comedian Rhod Gilbert on the people who inspire him, including Eddie Izzard, Nye Bevan and Rhod's primary school teacher.

A theme runs through the stand-up tonight. All three comics riff on the way people overreact to trivial things. For excellent Kerry Godliman, that means women who think they've lost their purse; for host Rhod Gilbert it's an altercation with the "travelling chef" in a train's buffet car about an egg and cress sandwich. Final act Jon Richardson serves up lovely micro-observations of his slobby housemates and their washing up: "You're doing a baking tray when there's still wine glasses!" he wails, and we feel his pain.

Frazzled Welshman Rhod Gilbert is our energetic host tonight, bringing us another slice of stand-up from the Hammersmith Apollo. Both Gilbert and guest Jon Richardson poke fun at their comic personas. Gilbert takes us through his anger management journal ("sort of a cross between Bridget Jones's Diary and Mel Gibson's"). Richardson makes light of his OCD, moaning about his messy flatmates ("adults who eat cereal at night-time"). Sandwiched between the boys comes likeable Kerry Godliman taking a pop at wedding proposals and bridezillas.

Rhod Gilbert on his earliest memories

Rhod Gilbert is hilarious and contrary. No-one ever doubted the first quality but, true to his nature, he's always denied the other - until now.