Scribd is rolling out a revamped version of its unlimited digital book service today. E-book subscription services are getting more popular lately, partly because Amazon finally starting to offer one of its own, Kindle Unlimited, last month. Scribd compete’s with Amazon’s service as well as with established rival Oyster. The Scribd service offers people a selection of over 500,000 digital titles, including books from major publishers as well as a number of bestsellers.