Summary: The digital book market has changed radically since 2017. With EPUB 3, mandatory accessibility and artificial intelligence, the openings for publishers have never been wider.
In 2017 we published an article on Medium about the opportunities digital books offered at the time. Almost a decade later the picture has changed dramatically. EPUB 3 has settled in as the industry's universal standard, accessibility has moved from a selling point to a legal requirement, and artificial intelligence has transformed publishing processes end to end. This article revisits that original piece and brings the conversation up to 2026.
EPUB 3 as the universal standard
When we wrote the original article, EPUB 2 was still widely used by Brazilian publishers. At that point the IDPF (International Digital Publishing Forum) was the organisation responsible for the format. A great deal has changed since. The IDPF merged with the W3C (World Wide Web Consortium), which took over the stewardship and development of the EPUB specification. That move brought the format into the web ecosystem, aligning it with the HTML5, CSS3 and WAI-ARIA standards.
EPUB 3 has become the standard accepted by every major distribution platform. Apple Books, Google Play Books, Kobo and Amazon (through the Kindle Publishing Format, KPF) have all adopted it as the basis of their ecosystems. That means a publisher producing a well-structured EPUB 3 can distribute to virtually the whole global market from a single source file.
The technical advantages are concrete: native support for semantic HTML5, accessibility features written into the specification, the ability to embed audio and video, richer metadata through ONIX and Schema.org, and the possibility of building rich reading experiences without relying on proprietary formats. For publishers still working with EPUB 2 or PDF as their digital base, moving to EPUB 3 is no longer a choice. It is a necessity.
Accessibility as a requirement, not an option
Where accessibility was seen as a competitive edge in 2017, in 2026 it is a legal obligation in several markets. The European Accessibility Act, which came into force in June 2025, requires every digital product and service sold in the European Union to be accessible. That includes digital books. Publishers exporting to the European market have to make sure their EPUBs meet the accessibility criteria set by the EPUB Accessibility specification and the WCAG guidelines.
In Brazil, PNLD Digital, the national textbook and teaching material programme, has for some years required digital educational material to meet specific accessibility requirements. That created a substantial market for publishers who invested in accessible production. Those who did not adapt are losing ground in public tenders and government contracts.
Beyond the legal side, the market of readers with accessibility needs is enormous. According to the World Health Organization, more than a billion people worldwide live with some form of disability. In Brazil, the national statistics institute IBGE puts the figure at around 18.6 million. Accessible digital books do not merely satisfy an ethical or regulatory obligation. They open a market the publishing industry has historically ignored.
Streaming and subscription models
The subscription model for digital books, still in its infancy in Brazil in 2017, has settled in for good. Amazon's Kindle Unlimited remains the largest global player, but platforms such as Skeelo and Storytel have taken a meaningful share of the Brazilian market. In education, Elefante Letrado and Árvore de Livros have established themselves as essential platforms for schools and school networks.
For publishers, subscription is a source of recurring revenue that complements unit sales. The key is understanding that books for streaming platforms have to be technically impeccable: rich metadata so they can be found, responsive formatting that works across devices, and accessibility built in so they reach the widest possible audience.
Self-publishing also continues to grow. KDP (Kindle Direct Publishing) and Kobo Writing Life let independent authors reach global markets without traditional intermediaries. Tools such as Reedsy and Draft2Digital make formatting and distribution across platforms straightforward. The digital publishing ecosystem has never been so open to anyone who wants to publish.
Artificial intelligence in publishing production
The deepest change since our 2017 article has come from artificial intelligence. At every stage of the publishing workflow, AI is streamlining processes, cutting costs and creating possibilities that simply did not exist a decade ago.
In audiobook production, neural speech synthesis has reached a level of quality that makes it viable for backlist. Volyo Audiobooks, developed by Booknando, lets publishers turn their titles into audiobooks with natural, expressive voices, opening up the audio format without the prohibitive cost of professional human narration for every title.
Automated image description is another field where AI is making a real difference. Booknando Scribe uses computer vision models to generate image descriptions in digital books, dramatically speeding up the work of making publications accessible. What once took specialist describers hours of manual work can now be done in minutes, with human review concentrated on refining the result.
In technical validation, Digital Preflight automates conformance checking of EPUB files, catching errors in structure, metadata and accessibility before distribution. That dramatically shortens the review and correction cycle that used to delay the release of digital titles.
AI is also changing publishing translation, metadata optimisation for discoverability in digital stores, predictive analysis of market trends, and even the generation of supporting material such as study guides and summaries. Each of these is an opportunity for publishers who know how to fold the technology into their workflows.
The opportunities are greater than ever
Looking back, the 2017 article was right about the potential of digital books. But even we did not imagine how far the picture would expand. Today's opportunities are incomparably greater. Publishers who invest in accessible digital production, multi-platform distribution and the intelligent integration of AI into their processes will be well placed to thrive in the years ahead.
Digital publishing is no longer a promise for the future. It is the present reality. Publishers who understand that and act strategically will hold a significant competitive advantage.
Booknando has followed this evolution since 2014. From the first EPUBs we produced to the AI solutions we build today, our mission has stayed the same: to help publishers turn their content into digital publications of real quality, accessible and ready for what comes next. If your publishing house wants to be part of that, we are ready to help.
