It was only meant to run for a few months, but seven years on the King's Emporium on Broadway is still going strong.
Barry Milner, who operates the bookshop, says when it started, he thought it wouldn't be open for long.
"I thought it would go for about six months really, to raise a bit of money for new projectors for the theatre and that would be it. But here is it still going years later."
Barry came up with the idea of the shop as a way to fundraise for the historic TET King's Theatre, which sits to the side and above the shop.
The theatre, the first in the Southern Hemisphere to show "talkies" or movies with sound, has now got those new projectors, thanks to the bookshop as well as funding from various agencies.
Rather than stop once those projectors were installed, the bookshop has instead gone from strength to strength, says Barry.
"The theatre always needs help, and the bookshop is one way to keep money coming in. Since we first opened, we have built up a good bank of customers, with many coming from other parts of New Zealand to the shop."
Barry says he often has collectors call him looking for something specific, and he enjoys being able to help them.
"I always find it satisfying to be able to find the right book for someone."
Thanks to regular donations of books from people, Barry says the shop is bursting at the seams.
"Right now, the store is beautifully full. So we are going to hold a book fair later this month, to clear lots of stock and to give people the chance to find some bargains while helping support the theatre, a part of Stratford's history."
The book fair will take place in the theatre itself, on the stage and Barry is confident there will be something for everyone on the day.
"As well as books we have 30 years worth of movie posters to be sold as well at the fair. We also have heaps of children's books so it is a great, cheap way to introduce children to some different authors, and stock up their bookshelves at home."