Winners of literary lottery that is Richard & Judy's book club

Since James Bradley's Gothic thriller The Resurrectionist was first published a year ago it has, to be kind, enjoyed modest sales. The tale of Edinburgh body-snatchers in the murderous era of Burke and Hare has sold fewer than 300 copies.

But that is apparently about to change. The title has been selected to feature on every author's holy grail: Richard & Judy's Summer Read. And unless he is very unlucky, Mr Bradley can expect can now expect to be selling 250,000 copies – much more than if he had won the Booker Prize.

Another novel on the list of pool-side recommendations is The Outcast, Sadie Jones's tale of a claustrophobic post-war Home Counties childhood. As one of six titles short-listed for the Orange Prize, The Outcast has enjoyed hardback sales of 6,000, but its inclusion in Summer Read could see sales rise tenfold. Both titles are now being rushed into paperback. Following in the footsteps of the success of Oprah Winfrey's book club in the US, Richard & Judy now wield unrivalled clout in the publishing world, with its annual Book Club and Summer Read delivering a sales boost of more than 300 per cent. Featuring on the list does not come cheap, however. Publishers have to be prepared to discount their books heavily – typically by around 65 per cent – to get them into the front of book stores, and are also required to contribute towards steep marketing costs.

Will Atkinson, sales and marketing director of Faber & Faber, which publishes The Resurrectionist, said: "The numbers speak for themselves. It's transforming for a book. Along with the big literary prizes, it's probably the most important promotional tool."

Although all publishers are allowed to submit up to six titles, independent publishers have struggled to get their books featured.

Hazel Cushion, managing director of the Welsh independent publisher Accent Press, said: "They all come from large publishing houses, which shows how very hard it is to be selected.

"From an independent publisher's point of view, it's really ruined the fiction market. So many people only buy two or three books a year and now they're from the Richard & Judy selection and they're not prepared to look outside that."

The power behind the Richard & Judy book groups is Amanda Ross, sister-in-law to the TV presenter Jonathan Ross and her husband Simon, managing director of Cactus TV, which produces Richard & Judy.

Last year, the most successful of the summer picks was The Memory Keeper's Daughter by Kim Edwards, which sold 701,000 copies, according to The Bookseller magazine. This was followed by The House at Riverton by Kate Morton, which sold 650,000 copies and Simon Kernick's Relentless, which sold 325,000 copies. Previous Book Club successes include Kate Mosse's Labyrinth, which became the fastest-selling paperback of all time after it was featured on the show in 2006, selling 1.3 million copies. Joel Rickett, deputy editor of The Bookseller, said: "The summer club was almost set up as a second string, but now has become equally important because summer reading is such a phenomenon. It's the second most important period of the year after Christmas.

"The average Richard & Judy book has sold a quarter of a million copies, which is higher than the average Booker Prize-winner. A spot on Richard & Judy is better than winning the Booker." But there is a question mark over whether Richard & Judy will remain such a powerful force in publishing when it moves networks in the autumn.

The programme attracts an average audience of 1.9 million to its 5pm slot on Channel 4, but later this year moves to UKTV, where it will go out at 8pm on a rebranded channel. UKTV Gold, the channel it is thought to be replacing, has had peak ratings of only 380,000 so far this year.