Tauranga women are rushing to read a raunchy romance novel dubbed "mummy porn".
The book, Fifty Shades of Grey, is a sadomasochistic story of sex between a 21-year-old woman and a mysterious billionaire. Millions of copies have sold world-wide.
Owner of Tauranga's Books A Plenty, Chris Baskett, said
she was about to do her third buy of Fifty Shades of Grey, by E L James, having sold out of the first batch, and quickly nearing the end of her second.
"It's one of those books that's crept up on us," she told the Bay of Plenty Times. "It's sold overseas, well. And we live in a technological age ... so (through the internet) we were reading about the book before it came into the shop."
Fifty Shades of Grey is notable for its erotic scenes. The second and third volumes are titled Fifty Shades Darker and Fifty Shades Freed respectively.
Ms Baskett said the second and third books in the trilogy were not as popular as the first, but still doing well. She had sold half her stock of the other two.
This week, the books hold the top three spots on the New York Times best-seller list. In New Zealand, 10,000 sales are expected in three to four weeks, which would put it at the top of the list, said publisher Random House NZ.
Fifty Shades of Grey has been dubbed "mummy porn" overseas because of its popularity among middle-aged women.
In Tauranga, Mrs Baskett said mostly women were buying it but some men were also customers.
"They were quite excited about it as well."
At $20, the steamy read is part of a wave of erotic fiction in vogue across the world right now, Mrs Baskett said.
The Fifty Shades trilogy took a non-traditional route to its paperback form, starting in e-reader form.
Mrs Baskett said despite its current popularity, there were other books in store much more popular.
One is "the very good literary book," The Forrests, by New Zealander Emily Perkins. The other is The Chaperone by Laura Moriarty - "which is another commercially available book but also extremely well written".
Owner of Paper Plus in Papamoa, Neville Butler, said the book had taken retailers by surprise. "Anything hot is usually on our group buying list a few months in advance and this one wasn't even on the radar." He had sold 37 copies in four weeks and was about to make his fourth order of the book.
"It's been massively popular. Everyone seems to be talking about it ... It (the trilogy) has been a phenomenon."
A spokesperson at Whitcoulls in Devonport Rd said the popularity of the book had dwindled since its debut in New Zealand about a month ago - but only slightly.
Tauranga City Libraries has two copies of Fifty Shades of Grey. Both are out at the moment and 17 people are on the waiting list.
In Auckland, there are 20 copies with 706 people waiting. After two days of sales in New Zealand, it reached No6 on our international bestseller list.
Reviews of the book have been mixed. While The Guardian of London called it "jolly" and "eminently readable", the UK's The Telegraph said the writing was "appalling."