It is being described as a “revolutionary moment in the history of bookselling”: a socially conscious alternative to Amazon that allows readers to buy books online while supporting their local independent bookseller. And after a hugely successful launch in the US, it is open in the UK from today.

Bookshop was dreamed up by the writer and co-founder of Literary Hub, Andy Hunter. It allows independent bookshops to create their own virtual shopfront on the site, with the stores receiving the full profit margin – 30% of the cover price – from each sale. All customer service and shipping are handled by Bookshop and its distributor partners, with titles offered at a small discount and delivered within two to three days.

“It’s been a wild ride,” said Hunter, who launched the site in the US in January. “Five weeks into what we thought was going to be a six-month period of refining and improving and making small changes, Covid-19 hit and then suddenly we were doing massive business.”

Initially starting with 250 bookshops, more than 900 stores have now signed up in the US. “We went from selling $50,000 (£38,000) worth of books in all of February, to selling $50,000 a day in March, then $150,000 a day in April,” said Hunter. By June, Bookshop sold $1m worth of books in a day. The platform has now raised more than $7.5m (£5.7m) for independent bookshops across the US.

“We were four employees plus me, working at home, getting up as early as we could and going to bed as late as we could, trying to make it all work. It was a real white-knuckle ride,” said Hunter. “But it was extremely gratifying because the whole time we were getting messages from stores saying, ‘Thank God you came along, you’ve paid our rent, you’ve paid our health insurance this year.’ If you’re going to have to work in insane circumstances and with huge amounts of stress, it’s good to be doing it in something you feel good about.”

Bookshop is a benefit corporation in the process of applying for B Corporation certification in the UK, created with the mission “to benefit the public good by contributing to the welfare of the independent literary community”. Rules state that it can never be sold to a major US retailer, including Amazon.

Hunter believes the reason for Bookshop’s quick success is readers’ fondness for their local booksellers. “Bookstores have been in trouble for a while because of Amazon’s growth, but this pandemic has really accelerated it. Amazon has gotten much more powerful, while there are 100-year-old stores that are hanging on for survival,” he said. “I think we were so successful because enough people were conscious of that, and wanted to rally around around their beloved bookstores, because they care about the world that we emerge from this pandemic into.”

Hunter had been planning to launch Bookshop in the UK in 2021 or 2022. But after seeing the success of the platform in the US, shops, publishers and authors in the UK asked him to step up the timeline. Bookshop.org launches in the UK on Monday, with more than 130 British bookshops already signed up and 200 expected by the end of the year. The UK arm of the company will be run by managing director Nicole Vanderbilt, the former international vice-president of Etsy.

“If you don’t get there before Christmas, and give people a way to support their stores and buy their gift books, then it’s gonna be really catastrophic for shops, which is why we’ve scrambled all hands on deck to get it up,” said Hunter.

Bookshops make no financial investment, with all customer service and shipping handled by Bookshop, and, in the UK, by distributor Gardners. The browsing experience is intended to “mirror the joy of discovering a new book in a physical bookshop”, says the company, with experts, rather than algorithms, doing the curating. Each independent that joins has its own “storefront” page, where customers can browse virtual tables of recommended books. For example, a user can see what the owner of The Shetland Times Bookshop (“Britain’s most northerly general bookshop, situated over 60 degrees north and closer to Norway than to London”) personally recommends, in lists such as “wonderfully funny picture books I’ve read to the bookshop staff”, and “books to help you take life in your stride”.

British booksellers and publishers have welcomed its arrival. “Being an independent bookseller has for so many years been such a David v Goliath battle that it feels slightly disconcerting when someone at last hands you a bazooka instead of you peppering away with your slingshot,” said Andy Rossiter of Rossiter Books in Ross-on-Wye.

Philip Gwyn Jones, publisher at Picador, described Bookshop as “a positively revolutionary moment in the history of bookselling in the UK, and in the evolution of the relationship between writers and readers”.

“It’s hard for us to compete with someone that’s got its own warehouse and sells books sometimes at a loss, or at very small profit margins. We just can’t do that. So it’s nice that Bookshop.org is going to rival Amazon in a way we couldn’t on our own or even collectively,” said Georgia Eckert, of Imagined Things bookshop in Harrogate. “You’ve got to have the reach, a site that’s big enough, run by a proper team of people dedicated to it. We’re all running our own businesses and haven’t got time to be doing that.”

• This article was amended on 5 November 2020 because an earlier version referred to Bookshop.org as a B Corporation. However, the company is in the process of applying for B-Corp certification in the UK. This has been corrected.