With 50,000 sales a month, Wool reached No. 1 on Amazon's science-fiction bestseller list as an e-book.

Twentieth Century Fox bought film rights, and Howey agreed in December to sell print rights to a traditional publisher while retaining electronic rights and profits - a first in the industry.

He joins Britain's E.L. James, whose Fifty Shades of Grey trilogy went from a free fan-fiction website to become the fastest-selling book in history, and American Amanda Hocking, who has sold more than 1 million copies of five fantasy novels since self-publishing the first as an e-book in 2010 and being picked up by print publishers.

In Australia, Matthew Reilly's international career as a thriller writer took off after a Sydney publisher spotted his self-published book in 1997.

Queenslanders Rachael Bermingham and Kim McCosker sold 2.5 million print copies of their self-published 4 Ingredients recipe book after publishers rejected them.

The rapid rise of e-books and e-reading devices, as well as print on demand, has made self-publishing easier and more affordable for anything from commercial fiction to business and self-help guides, private memoirs and family photo books.

In the US, 253,626 print and e-books were self-published in 2011, a growth of 287 per cent since 2006, according to data-collector Bowker.

Thorpe-Bowker's Australian figures show 2788 publishers released just one title in 2011, representing 67.5 per cent of all ''publishing entities'' and 14 per cent of titles produced. Many were self-publishers, they conclude.

''We've had more than a 50 per cent increase in the past 12 months in people who want to know about the opportunities and companies we would recommend for self-publishing,'' said Maree McCaskill, the chief executive of the Australian Publishers Association.

Self-publishing companies are proliferating, including offshoots of mainstream publishers and booksellers such as Amazon's CreateSpace and Dymocks' D Publishing.

It's easy to see benefits in publishing your own book: avoid the disheartening slog of proposal and rejection; publish your brilliant words without an editor's interference; keep the profits rather than receive a measly 10 per cent royalty.

More writers are self-publishing because technology and economic downturn have hit the book industry and made publishing companies more cautious. Advances are smaller and contracts harder to get.

Terence Tam, the founder of BookPal, a self-publishing company in Queensland, said ''99 per cent of manuscripts are rejected by publishers so we help weed out books and give them an opportunity to get published''.

However, self-publishing can still be relatively expensive, technically challenging and time-consuming. Commercial success is rare in a market crowded with amateur efforts.

Former Australian rock'n'roller Robert James says he unsuccessfully approached publishers 30 times before self-publishing his metaphysical thrillers with CreateSpace.

He says he has sold about 3000 print books in the US and 200 in Australia on Amazon, where he makes $10 a copy after costs. But, he says, ''I'm broke and I need to sell more books''.

Like most self-publishers, he has learnt distribution and publicity are tough without a big firm's backing.

Sydney's Pnina Jacobson and Judy Kempler self-published their book of Jewish recipes and life stories One Egg Is a Fortune last year to raise money for aged care.

They employed a professional food stylist, photographer and designer, and their handsome book has won six awards. But after ''a huge investment'', they have yet to break even and are surprised at how hard it is to get attention from media and bookshops.

Ben Hourigan, IT manager at a Melbourne magazine company, self-published Kiss Me, Genius Boy, the first part of his 150,000-word romantic comedy, to impress a woman whom he'd told he was a novelist.

He has sold about 200 copies and has plans for the next instalment.

He has also built a profitable freelance business that includes helping other writers to self-publish for a fee plus 25 per cent of their net revenues.

''Even though Amazon and Apple present it as an easy process, it's far from easy,'' he said.

Newcastle communications worker Rob Towner's self-published picture book Romy's Garden Adventures: Christmas City was Amazon's No. 1 downloaded children's ebook, among the top 10 children's books and top 100 titles in the lead-up to Christmas.

The catch? Towner was giving his book away as a pre-Christmas promotion. Now buyers have to pay $2.99 for the ebook or $11.95 for the paperback.

Towner has had ''a ton of success using alternative channels of communication'', but he says it's not about money or sales, ''it's about the love of telling a story''.