In a note to clients — as reported by “AllThingsD” ( — Global Equities Research analyst Trip Chowdhry estimates that Apple saw 90,000 downloads of the iBooks Author textbook creation tool announced last week. He also thinks that over 350,000 textbooks were downloaded from the company’s iBookstore with the first three days of availability.

Global Equities Research says the supply chain markup on textbooks ranges between 33% and 35%. “[This is] a recipe for Apple’s success in the textbook industry,” says Chowdhry.