Document-sharing site Scribd launched three years ago with the idea of making PDFs and other text-documents more Web-friendly. Now three years later, the site stores more than 10 million documents, which in turn have been embedded more than 10 million times across the Web. Scribd says it reaches more than 50 million people a month worldwide (Quantcast).
Scribd is also making a big push into mobile reading by making it easy to send documents to avariety of mobile devices, including iPhones, Android phones, Blackberries, Kindles, and Nooks. The company has raised $13 million total from Charles River Ventures, Redpoint, Marc Andreessen, Jeff Jordan, and David Sacks (who recently joined its board).