Amazon has unveiled a web-based service to support its existing Kindle e-reader, a day after Google launched its eBooks cloud-based ebookstore.
Kindle for the Web is nearly identical to Google eBooks and signals renewed competition in the e-reading market, according to the New York Times.
But Amazon's new service fits into the Kindle's established "buy once, read everywhere" strategy with all features automatically synchronised across all Kindle hardware and third-party platforms such as iOS, Android and BlackBerry.
The most important difference to the Google product, said the NYT, is that independent third-party publishers and authors can now sell content directly on their own sites, earning them referral fees through Amazon's Associates Program, whereas Google eBooks has not yet developed a third-party seller model.
Google may be betting on winning subscribers from its cloud-based Google Apps services and the fact that it has already digitised nearly 15 million books since 2004 through its separate Google Books project, which will enable it to offer 3 million titles from the start, said the NYT.
E-reader sales are set to reach 6.6 million units in 2010, up 79.8% from 2009 sales of 3.6 million, according to research firm Gartner.