The website currently archives digital records for 4.2 million books, collected from 10 million different sources. For instance, this entry on the obscure title, “A master class in brand planning: the timeless works of Stephen King,” contains summaries, notes, classification, book comparison, subject listings, library holdings, and links to buy the book online.
Here’s more from the site: “ISBNdb.com gets the data in a unique way – it scans libraries all across the world for book information. The scanning is random and similar in a way to how general purpose web search engines scan web sites. Scanned results are then parsed and stored in a searcheable and browseable database that you see here on ISBNdb.com. An attempt is made at cross-indexing the database by author, publisher, category and so on. Cross indexing is still a work in progress and is likely to improve as the time goes on.”