The idea of promises - or skills - auctions, where the lots under the hammer are offers by individuals to contribute talents or experience, is anything but fictional, however. According to organisations that have used this form of fund-raising, Ambridge should have done better than the pounds 300 it raised.
'We have just organised what we called a 'skills and thrills auction' towards buying a second-hand pick-up truck for an agricultural and tree-planting project in northern Ghana,' says Ruth Coffey of the Leeds group of the charity Tools For Self-Reliance.
The auction was held in two parts during June and July and according to Ms Coffey raised more than pounds 2,000. 'We had 75 lots on offer: juggling lessons, baby-sitting, a day's caving for a beginner, as well as a chance to pose for a photograph with the Leeds United team . . . Someone offered to do the cooking for a meal for 20 people. That went for pounds 100.'
Ms Coffey says the auction provided the opportunity for supporters on low incomes to bring in much more for the Ghana project than they would have been able to donate.
The first task for a group planning a skills auction is to attract enough auctionable lots. 'The first reaction of most people is, 'I haven't got any skills.' But once they have had time to think, it is not that difficult to get offers,' says Judy Maxwell of Leeds Women Against Apartheid, another group that has arranged successful skills auctions. Among the lots they have auctioned have been offers to paint a picture of a house, to run a children's party, and to provide breakfast in bed.
Ms Maxwell says her group's auctions usually raise about pounds 1,000 from about 30 lots.
'The auctioneer needs to be happy to stand up and chivvy things at first, then it just takes off,' she says. 'It's a very good fund-raising device.'
According to Lee Comer, who arranged a skills auction in the small Yorkshire town of Hebden Bridge, West Yorkshire, earlier this year, it takes at least two months to arrange a successful event. Her auction, which raised pounds 1,200 for two local campaigns, had about 60 lots, including bridge, golf and wind-surfing lessons, a chauffeur-driven day out, and a consultation with a local doctor.
The auction venue, a local pub, may have helped: 'The drink probably helped increase the bids,' she admits. However, all the money eventually came in, she says, even from those whose bids may have been a trifle over-enthusiastic.
She was not impressed by the efforts of the radio residents of Ambridge: 'I would say it wasn't worth the effort - pounds 300 is terrible. You can get that from a jumble sale.'
Simon Frith, the radio script-writer who introduced the auction story-line, admits that the takings in Ambridge seem on the low side.
He says he participates in an annual skills and promises auction run by the Church of England school in his Gloucestershire village.
'It is the biggest fund-raiser for the school. This year it raised over pounds 1,000. Absolutely everybody volunteers.'
His promise for this year's sale was not, however, an opportunity to write your own plot for an Archers episode; instead he offered 25 lbs of apples from his orchard.