Where to send your old Dan Brown books ... an Oxfam bookshop. Photograph: David Sillitoe
Dan Brown might be one of the world's bestselling authors but it turns out that readers aren't too keen on keeping his special blend of religious conspiracy and scholarly derring-do on their shelves once they've bought it.
Brown, who has sold more than 81m copies of The Da Vinci Code worldwide, has been revealed as the most donated author to Oxfam's 700 high street shops. With just four books to his name – although his long-awaited fifth The Lost Symbol is published next month – Brown did well to see off competition from John Grisham, author of more than 20 and 
the second-most likely writer to be ditched in a charity shop by readers.
But as secondhand bookshop shelves flood with battered editions of Angels and Demons and Digital Fortress, Brown can comfort himself with the fact that he's also Oxfam's 2nd most bought author: there are, apparently, still readers out there who have yet to follow the adventures of the dapper symbologist Robert Langdon. There's no such consolation for Grisham, whose legal thrillers fail to make Oxfam's bestseller charts at all.
"There's no question that when you go into the back room of Oxfam shops there are many Dan Brown books," said Oxfam's director of trading David McCullough. "But he's also very high on the bestseller list so there is a useful recycling exercise going on – it's not just people saying 'I've read The Da Vinci Code and now I must get rid of it'."
Ian Rankin, whose dour, boozy detective John Rebus is no Robert Langdon, tops Oxfam's bestseller list, which the charity says is the first ever high-street secondhand bestseller chart. "It's always good for an author to know that their books are popular," said the Scottish author, who will unveil a new policeman hero, the teetotal Malcolm Fox, next month. "With Oxfam, it's also heartening to realise that each book donated and bought is helping such a worthwhile organisation."
Stephenie Meyer, author of the Twilight series and instigator of myriad teenage crushes courtesy of her sparkly vampire hero Edward Cullen, is also sitting high in Oxfam's charts, nestling between Bernard Cornwell and Terry Pratchett.
Margaret Atwood, meanwhile, winner of the Booker prize and author of a host of critically acclaimed works of fiction, scrapes into the list in 8th place, keeping unlikely company with thriller powerhouse James Patterson – currently producing at least 8 books a year thanks to a horde of co-writers – and Jodi Picoult, never afraid to jerk a tear or pile on the plot twists.
"We just need to dispel the idea that we are sitting there in Oxfam with only first editions of literary gems – actually we've got shelves of really good fiction," said McCullough. "Waterstone's might be more upset than secondhand booksellers," he added, referring to the recent slew of complaints from secondhand booksellers that the charity is stealing their business.
Oxfam, Europe's biggest high-street retailer of secondhand books and the third-biggest bookseller in the UK, launched a drive for book donations in May ahead of its first national book festival, Bookfest, in July. Authors including Joanna Trollope, Philip Pullman and Jonathan Coe all lent a hand in shops across the country as part of the festival, and the drive saw book donations rise 40%, with sales up by more than 10%.
Rare books and first editions have also been pouring into shops since May. Ten of the most sought-after editions have raised more than £4,500 for the charity between them. A first edition of Lord of the Rings sold for £800, a first edition of Watership Down brought in £500, Sylvia Plath's Ariel sold for £350, Ian Fleming's From Russia With Love for £300 and a second printing of Martin Chuzzlewit for £200.
Oxfam, which has more than 130 specialist bookshops and stocks books in almost all of its 700 stores, sells £1.6m-worth of books a month – equivalent, it says, to 50,000 emergency shelters, 64,000 goats or safe water for 2.1 million people.
The most donated authors to Oxfam shops so far this year:
1. Dan Brown
2. John Grisham
3. Ian Rankin
4. Danielle Steel
5. Helen Fielding
6. Stephen King
7. JK Rowling
8. Catherine Cookson
9. Patricia Cornwell
10. Mills & Boon
The Oxfam shop bestseller list:
1. Ian Rankin
2. Dan Brown
3. Bernard Cornwell
4. Stephanie Meyer
5. Terry Pratchett
6. Khaled Hosseini
7. Helen Fielding
8. Margaret Atwood
9. James Patterson
10. Jodi Picoult
The top 10 most valuable donated books since May:
1. JRR Tolkien, Lord of the Rings – first edition, sold for £800
2. Don Giovanni sheet music – first edition, sold for £750
3. Sowerby's Catalogue of Shells – sold for £600
4. Richard Adams, Watership Down – first edition, sold for £500
5. Handbook of Indian Dances - first edition with hand-blocked prints, sold for £500
6. Richmal Crompton, Just William - first edition, sold for £440
7. Sylvia Plath, Ariel – first edition, sold for £350
8. Ian Fleming, From Russia With Love – first edition, sold for £300
9. Charles Dickens, Martin Chuzzlewit – second print, sold for £200
10. WE Johns, Biggles in Australia – first edition, sold for £150
